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More FAQs about ORP, Ozone, Ozonizers Application/Installation

Related Articles: Reduction Oxidation Potential, RedOx: A Very Valuable Tool For Assessing, Assuring Maine Aquarium Health, ppt. presentation, Part 1, Part 2, Part 3, by Bob Fenner, Physical Filtration, RedOx,

Related FAQs: Ozone, Ozonizers 1, Ozone, Ozonizers 2, Ozone 3, Rationale, System/Selection, About Dryers, Measuring, Maintenance/Repair, Reduction Oxidation, & Marine Test Gear 1, Marine Test Gear 2, Marine Water Quality, Marine Water Quality 2, Marine Water Quality 3,

Is there, near somewhere you want to be? A Clavelina (tentative ID) species surrounded by sponges and more.

Starting Ozone    3/29/18
Hello Bob,
I hope this finds you well.
<Thank you John; getting better>
Today I am going to fire up my ozone for the first time ever. I have a 200mg unit that has a built in ORP controller. I currently have no idea what my sitting ORP is in the tank.
<Mmm; I would not only measure this... a few times per day, night for a while... AND record your readings, observations, including time of day the readings were taken; but continue to measure when the O3 unit is employed for a while>
In the past my ORP has averaged about 350-360 without any ozone.
<Good value range>
Once I start that unit it will be going through the Venturi of my skimmer. Any thoughts on how much ozone I should set the unit to deliver?
<Start on a low/er setting, measuring ORP in the system again in the AM, afternoon and evening for a few days before cranking up further. You will find there is a daily cycle as well as damping with feeding most foods, raising via water changes...>
I believe I remember you saying to not allow the total ORP go above 400, please correct me if I’m wrong.
<This is the/an ideal upper limit, yes>
What is a good starting point to dial the ozone output to.
<Mmm, ten, twenty percent per the dial...>
The tank is 750 gallons and the ozone generator and the sump it’s going to inject into are both outside my house on the porch. Thank you in advance.
<Cheers, Bob Fenner>

Re: Starting Ozone    3/30/18
Thanks once again Bob.
<Certainly welcome>
Re: Starting Ozone    3/30/18

Good morning Bob,
<Hey John>
First I need to apologize for continued ozone questions but this one has me stumped.
<No worries. Have been spending days almost entirely stumped recently. Thank goodness this IS an area I am familiar with>
I am setting up that ozone generator at the moment. It’s a 200mg Enaly with built in ORP controller. I just took a brand new probe out of the box and hooked it up.
<Mmm; put this in the sump, in an area where it won't get smacked. Attached to the side with the suction cup>
I wanted to see what my baseline ORP was before adding ozone. I am getting a flat reading of 125-130 in my 750.
<Yes; low... the previous value range you sent along seemed unrealistically high>
I’m having a really bad time accepting that as accurate. There is no calibration option on this unit that I’m aware of. I’ll try to attach a pic. Any thoughts or suggestions?
<Yes... Am hoping your local higher end reef/fish store has ORP use... or another nearby aquarist; where you can check your checker. Do some sort of calibration. Otherwise there are such things as standard ORP solutions: https://www.google.com/search?q=orp+standard+solution&oq=ORP+stan&aqs=chrome.2.0j69i57j0l4.4527j0j7&sourceid=chrome&ie=UTF-8
As always, thank you.
<I would only trust the probe if it's been checked either against one of known use or a standardized solution John. I don't think you can/will "get into trouble" with this ozonizer, cranked all the way up to maximum (200 mg/h) setting period, but better to know here. Bob Fenner>

Re: Starting Ozone    3/30/18
Thanks Bob. I have a buddy down the road who has an apex with ORP probe. I’ll run it over there and see how it compares.
<Ah, good>
The guy I bought this unit from said it can take several days for the probe to stabilize.
<Some probes it does take minutes; others come with pre-moistened end>
Not sure if I agree with that opinion or not?? I can see an adjustment period but not sure about a few days....
Thanks Bob!
<Welcome John. You may well have this low ORP... Currently. BobF>

Re: Starting Ozone       3/31/18
Thanks Bob. I guess I should have mentioned that the tank has only been up and running for a month. Not sure if that should be taken into consideration or not...
<It does... new/er systems almost always have high/er and less steady ORP signatures; old/er ones lower and more stable>
also the probe did come with the tip in solution.
<Ahh; then it is likely registering properly... NOT necessarily accurately. Precision is not accuracy>
That’s why I thought it would be accurate or pretty darn close out of the box.
<Agreed. B>
Re: Starting Ozone       3/31/18

Thanks Bob. I’ll get it figured out one way or the other.
<I have high confidence in you>
Re: Starting Ozone       3/31/18
Hey if you’re interested here is a video of my tank. Finally finished it today.
<Ah, very nice; like the central arch work. Am hopeful that ozone use will improve water quality here, resist the activity, influence of your soft corals, aid in resisting, perhaps improving the HLLE on your Yellow Tangs. Bob Fenner>
<<File too large to share>>

Ozone is up and running          4/1/18
Hey Bob.
So I just cranked my ozone generator on. As mentioned I am running it into a ozone port on the Venturi on skimmer. I know you have covered this with me but if you would just comfort me please.... just to be clear, you said that the skimmer discharge DOES NOT have to go over carbon before reentering the tank, correct?

The sump and skimmer are outside the house so I’m not concerned about O3 in the house, just want to make sure I understood you crystal clear that I don’t need any carbon to scrub it before it goes back in the tank.
Thanks for holding my hand on this Bob. I really appreciate it sir.
Thank you,

ORP level    8/11/14
Hi - I have a 200 gal reef tank that I just started monitoring orp on with an apex controller.
<Good move>
Levels were between 360-380.
<Good values, range>

I then added a uv sterilizer that may be a little over sized for this tank. I added a CoraLife turbo twist 12x which is 36 watts. It calls for a 400-1200 gph pump. The pump I have been running with it is a little weak running 250 gph. Since then I have notice orp levels between 450-495.
<Ah yes... many small ozone generators utilize UV lamps for O3 production... This value, range is not surprising, and not trouble... will drop 50 or more units in time>

I also noticed that when I do a water change the orp levels drop to like 380 and then rise over the next day back to like 470-490.
<Yes... new charged particles interacting, dropping existent out>
My coral and fish seem to be fine. I suspect it's the uv sterilizers strength and low flow that's causing the high orp levels. Is is possible to maintain normal orp level while still using a uv sterilizer?
<Oh yes; again; not to worry. Thank you for sharing. Bob Fenner>
Re: ORP level
Thanks for the response. Can you help me understand why I shouldn't worry about this.
<Mmm; yes... whether millivolts per cm. or milli-Siemens/ the upper value you list is not "that" high... And once the more easily "combustible" materials are consumed, this value will drop>
I actually unplugged my uv sterilizer tonight and will purchase one that is not over kill for this tank size. I did a small water change (15 gallons)tonight. The orp levels went from 490 to 420 but even with the uv
sterilizer unplugged the orp is slightly rising again only hours after the water change. Also their is an inverse relationship between orp and ph, correct?
<Mmm; actually; again, over time, application they are stair-stepped>
I notice my ph going down as the orp increases.
<Yes; typical in newly ozonized systems. Bob Fenner>

Ozone application over 300mv      3/9/13
WWM Team,
I have a question regarding the proper application of ozone because my reef is consistently showing an ORP reading around 330mv (with regular calibration).
 The Ozone generator never turns on because I have the controller set to engage below 300 and I am wondering if there is a benefit to manually inject some ozone into the skimmer even with an existing RedOx level above 300mv?
<Some; I'd keep the overall reading under 400 mv; as gone over on WWM. Bob Fenner>

Ozonizer and Diffuser     3/13/13
Hello again to all crew and Mr. Bob.
The last 2 days I am reading about ozonizers and what is the best way to install it.
<Nice. Can be a nice addition or quite problematic/dangerous>
I am sure that installing it in your skimmer will do great work as it is wrote again on WWM. Ok.Understood.
<For certain>
Is there any better diffuser for ozonizers?? I read about wooden diffusers but I am not sure if it is better or not. Will this wooden diffuser be installed directly into the tank??
<Directly into the tank? No. Wooden air stones are very efficient but need frequent replacement. Likely something you would prefer avoiding. You will need a RedOx Controller of sorts. The ozone is essentially "pumped" into your skimmers air intake. Your skimmers method of fractionation (needle wheel etc) does the diffusing for you>
I am a little confused here.
<Ozone can be a tricky beast to concur>
Thank you in advance once again
Best regards
<The hardest and most important part about using ozone is the amount of which you are "dosing" into your skimmer. What model of skimmer do you plan to use ozone with? -NateG >
Re: Help Needed!!   3/19/13
Ozonizer and Diffuser

<Hi Kostas>
Thank you very much for your answer and I am sorry for my late reply but I wasn't anywhere near my pc.
I will be using a Deltec MCE600 at a 400 litres system , 200 litres ain display and 200 sump.
<If you maintain constant back pressure on your skimmer and clean it often, it will be quite capable of handling your system without issues. Even with a very heavy bioload ozone is overkill imo. Ozone certainly has its applications but will be costly and quite risky to run on a system this small. That skimmer should be a standalone workhorse here. >
Best regards
<Do you have the display and sump built/set up yet? Send a pic of what you've got. As well as more details on the rest of the equipment you will be using. Would be very helpful. NateG>

Ozone on 2000 gallon tank, ap. f'     4/10/12
Good afternoon!
I have a 2000 gallon cylinder tank setup and I have been experimenting with using larger amounts of ozone than usual.  I have an eight gram per hour ozone unit with variable output running using an oxygen concentrator. 
Right now the ozone is injected into a side stream from the sump into 200 feet of Kynar 1.5 tubing.  Then the gas is separated and the water is filtered through a carbon bed.  I have been using a Total Chlorine test to test for ozone produced oxidants and I have been having trouble keeping them low while raising ORP.  My ORP is tested using two high quality ORP probes.  I have a limited knowledge of chemistry but I have seen some information on the web of possibly using UV to destroy these oxidants.
<Mmm, I'd stick w/ your current protocol. MUCH more reliable>
 Do you have any experience or knowledge regarding the use of UV to remove these oxidants?
<Yes; though mostly theoretical. Am the author of the pieces on WWM re O3, ORP applications>
If so can you explain how people have implemented them?  From what I read it seems you would need a group of successive UV units at different wavelengths.
Mischa Deeter
Austin, TX
<Mmm, the/an explanation would take longer than I have today... There are standard texts in our (ornamental) and related fields re the topic. Again, I'd stick w/ the diffusion and removal S.O.P. you detail. Much less fraught w/ potential issues. Bob Fenner>
Re: Ozone on 2000 gallon tank    4/20/12

Thanks for the reply.  I have replaced the coiled tubing I was using to react the ozone with a 500 gallon tank.  Can you recommend a flow rate through the reactor based on your experience?
<I would measure the ORP in the main/display system... IF biomass, feeding, maintenance is "regular"/constant, I'd in turn set the O3 production to keep it/this under 400 mv/cm... Please read here: http://www.wetwebmedia.com/redoxinst.htm
and the linked files above. Bob Fenner>
Re: Ozone on 2000 gallon tank    5/1/12

I have the new large ozone reactor setup and there are a few things I wanted to get your input on.  I'm using 8 grams of ozone with a 500 gallon reaction tank with a flow rate of 1000 GPH.  Right now the water leaving the reactor has an ORP of 680 or so.  After it is passed through carbon the drops to 375 and the tank's ORP is 320.  I'm not sure how I would get the tank water to 380 ORP without letting some of the oxidants into the tank.
Any input here?
<Like what? Have you read where you've been referred?>
My second question is do I need to worry about removing the pure oxygen from the water?  Right now it's around 11ppm in the tank, measured with the pinpoint sensor.
<... what? No... How is it you're associated w/ this project knowing so little? B>
Re: Ozone on 2000 gallon tank
The tank was empty in the living room of the house when I moved into.
Since it was there I decided I wanted to make it work and have been learning and working on it for 9 months in my spare time.
<Ahh; such a large system, I took it you were in the industry or that this was a public aquarium set up>
 As far as the ozone question, I thought since you have seen more setups and had more experience with results you may have some recommended modifications to my setup. 
<Not w/o knowing much more; no. Ozone can be dangerous and I am wont to make blanket statements re w/o knowing much more>
As far as the oxygen comment I read an article that mentioned oxygen content of 11ppm and higher has had adverse effects on fish.  Sorry for wasting your time with the questions and I do appreciate greatly all the information you have made available on your site.
<I would have someone who knows what they're doing come on out (an aquarium service company) and go over what you have there... In person. B>
Re: Ozone on 2000 gallon tank 5/2/12

 I do have the best aquarium company in Austin working on it but they have very limited experience with ozone and oxygen.  One last question.  Isn't using ozone essentially the same as using a salt chlorine generator?
  it seems like using a salt cell would be a cleaner more efficient way to accomplish the same thing.  Have you heard of anyone doing this?
<... of using a NaCl generator? Yes... We need to start back a bit, quite a bit re means to generate high water quality. I would definitely stay w/ the O3 system you have now. B>

Quarantine and Ozone 3/26/11
Good morning aquarium oracles,
<Mmm, I can almost see where this is going '/;>
I had an idea that I wanted to sanity check you....I this idea after working all night so sanity is sometimes questionable at that point. I have reef system with approximately 300 gallons total water volume. I have over time become somewhat paranoid about my quarantine procedures and have separate tanks for quarantining fish and corals. I have the frag tank I use as my coral quarantine tank plumbed in such a way that by opening two valves I can connect it to the main system,
<Ahh, excellent... AFTER the absolute separation, you can easily mix/blend water here... A VERY good idea>
I use this so after my quarantine time is over and I am comfortable that there are no bad guys riding in on my corals that I can open the valves and it becomes the same system making acclimation
to the main system easy, the connection only does about 10 gallons an hour so it does a good job of slowly matching parameters between the tanks.
On my main system I of course have ozone on it. The way I have the ozone is a pump with a venturi (that is connected to the ozone) runs through 100 feet of coiled flexible PVC (for nice long contact time between water and ozone) then runs through a reactor with carbon before returning back to my main tank. Flow through ozone system is about 100 gallons an hour. My idea is to hook up the return from the frag tank to a PVC T that's connected to the ozone pump. with the difference in flow rates this would have 100% of the return water from the frag tank go through the ozone reactor and carbon.
I was thinking that by doing this I could run the two systems connected all the time so that while in quarantine the corals would be able to benefit from the much better water quality I am able to maintain in my main system without worry about introducing bad things into the system. So my question is: is this a good idea?
<I would still keep these systems separate during acclimation/isolation periods for new stock; connected otherwise>
would the ozone and carbon combination kill and catch any bad things that could come in on coral and the live rock it is attached to?
<Some, not all by far. Protozoans "on down" would not likely make it through, but worms, mollusks, crustaceans... would>
My goal is to get my corals the best water quality possible without putting the main tank at risk to diseases and parasites.
Thank you for your time, I don't know what I would do without you.
<Or I/we w/o you. Bob Fenner>

Re: red sea clown pair not eating, O3 toxicity - 10/10/10
Hi Bob
<Howdy Jim>
Many many thanks for your reply. I have found out why the clowns weren't eating. I had put my ozone unit (incidentally a TMC unit which was a really good price) dosage up too high too quickly... 150mg from 75 mg. Here's a warning about ozone making toxic water conditions.
<Ah yes... see my article and ppt on WWM re>
Once I had reduced this to 75mg all the fish were back to normal feeding and have been Ich free for about a day now (notch that up to experience). I will still consider moving the clowns for treatment if the Ich returns.
Now you say that clowns will not settle with triggers 'period'. I have to say I had clown fish and triggers together in my last setup with no problems and my Humu Humu is small (2inches).
<So far... Do keep an eye on the Rhinecanthus... all Balistids...>
I suspect this is a wait and see exercise. I am a very big fan of triggers as they have loads of personality. My system is 130 (US) gallons with a sump so I feel has ample space to cover his growth.
If my log book serves me right I did end up (much to my late wife's chagrin)
removing my previous Picasso due to him eating all my feather dusters.
Now as I have a quarantine tank it is only 15 gallon. Is this sufficient?
<For treatment of these three fishes at the stated sizes, yes>
If the Ich returns I will quarantine the clowns and leave the trigger as I feel it is more hardy.
I don't think the 15g quarantine will take all three fish am I correct?
Sorry but I am limited on space....this is the UK guys!!!
Thanks once again.
<Welcome! B>

UV sterilizer use with Ozone Generator - Sure, just realize that they do two different things. 7/26/2010
<Hi Jeff.>
I've been searching the internet for the last couple hours trying to find an answer to my question with no avail. I do believe I've found the answer before, but I don't remember.
Anyway, I started using an Ozone Generator a few months ago. It's made by Supreme Aqua. I noticed a few weeks ago that the JG fitting on my AquaC EV-180 Skimmer had disintegrated .
<Not uncommon with ozone, it is a very strong oxidizer, and can destroy most plastics within a very short period of time. You really want fittings made out of a material called "Kynar" as it is ozone resistant>
I talked to Steve with AquaC and he promptly sent me out two replacement fittings. However, after cleaning off the skimmer, I saw the body of the skimmer was cracked across the spot where the JG fitting screws in and all
the way across the body and down the side. It was not cracked all the way through, however it looked like it might not be far from splitting in half.
<Hmm... may be a function of the JG fitting being tightened too much rather than ozone.>
I was greatly alarmed. I contacted Jason at AquaC and he gave me his cell number and sent me a replacement skimmer. Great Customer Service!
<Aqua-C is known for their excellent customer service. I'm pleased to say I'm not in the least surprised that you got such an excellent response.>
After hooking up the new skimmer, I decided not to take a chance with my current ORP controller and Ozonizer .
I ordered a Ozotech Poseidon along with a Neptune Apex controller.
<Good brands, but I don't see the point, obviously the one you had was producing ozone very well. The JG fitting failed because it was exposed to ozone, not because your ozone generator was an off brand.>
My current controller is off brand and was shipped from overseas.
<Most of them are made and shipped from overseas.>
I'm not sure it's the culprit , but I don't see anyone else using that brand or the off brand ozone generator so I'm not taking any more chances with cheap equipment.
<I use an Enley ozone generator I picked up on EBay over a year ago for less than $100 USD. Still going strong running 24 hours a day.>
My question is do I need to run my UV sterilizer along with the Ozone generator or is it redundant.
<They do two different things really. Ozone is used to burn off additional organic compounds in the water. UV is used to kill off bacteria, viruses, and the like. UV lamps DO produce ozone, but in a very small amount.>
Thank you,
<My pleasure.>
Re: UV sterilizer use with Ozone Generator Follow Up. 7/30/2010

<Hi Jeff.>
Thanks for your help.
<No Problem.>
Do you have any idea where I can get the kylar <Kynar> fitting to fit the AquaC EV-180 skimmer. I look on the Internet and at some plumbing sites, but I couldn't find the right fitting. Thanks!
<Check http://www.ozonesolutions.com/ They sell all things ozone related.
they are a little pricey, but that have most everything.>
- Jeff

UV sterilizer use with Ozone Generator - Sure, just realize that they do two different things. 7/26/2010
<Hi Jeff.>
I've been searching the internet for the last couple hours trying to find an answer to my question with no avail. I do believe I've found the answer before, but I don't remember.
Anyway, I started using an Ozone Generator a few months ago. It's made by Supreme Aqua. I noticed a few weeks ago that the JG fitting on my AquaC EV-180 Skimmer had disintegrated .
<Not uncommon with ozone, it is a very strong oxidizer, and can destroy most plastics within a very short period of time. You really want fittings made out of a material called "Kynar" as it is ozone resistant>
I talked to Steve with AquaC and he promptly sent me out two replacement fittings. However, after cleaning off the skimmer, I saw the body of the skimmer was cracked across the spot where the JG fitting screws in and all
the way across the body and down the side. It was not cracked all the way through, however it looked like it might not be far from splitting in half.
<Hmm... may be a function of the JG fitting being tightened too much rather than ozone.>
I was greatly alarmed. I contacted Jason at AquaC and he gave me his cell number and sent me a replacement skimmer. Great Customer Service!
<Aqua-C is known for their excellent customer service. I'm pleased to say I'm not in the least surprised that you got such an excellent response.>
After hooking up the new skimmer, I decided not to take a chance with my current ORP controller and Ozonizer .
I ordered a Ozotech Poseidon along with a Neptune Apex controller.
<Good brands, but I don't see the point, obviously the one you had was producing ozone very well. The JG fitting failed because it was exposed to ozone, not because your ozone generator was an off brand.>
My current controller is off brand and was shipped from overseas.
<Most of them are made and shipped from overseas.>
I'm not sure it's the culprit , but I don't see anyone else using that brand or the off brand ozone generator so I'm not taking any more chances with cheap equipment.
<I use an Enley ozone generator I picked up on EBay over a year ago for less than $100 USD. Still going strong running 24 hours a day.>
My question is do I need to run my UV sterilizer along with the Ozone generator or is it redundant.
<They do two different things really. Ozone is used to burn off additional organic compounds in the water. UV is used to kill off bacteria, viruses, and the like. UV lamps DO produce ozone, but in a very small amount.>
Thank you,
<My pleasure.>

ozonizer question, Fittings disappearing 4/2/10
Hi all !!
having trouble finding out why this happened. I got a Ozotech 150 ozonizer this past Jan. I bought ozone safe fittings & tubing that were rated "good" resistance to ozone. The tubing has norprene written on it but the black connectors/fittings don't have anything written on them. Last week I started smelling ozone. Found one of the connectors had burst. I turned the ozonizer off & checked all the fittings, there are 3 others and all were softening to the point that when I touched the end the black stuff stuck to my finger.
The tubing seems unchanged. I contacted the company I got it from & they said that they have never had this happen in years of selling these parts.
<? Doubtful>
I asked Ozotech for a instruction book in Jan for this unit but still haven't gotten one. I have been using the ozone at 100% but after reading your site it doesn't seem like that was a factor.
<Well, the higher the concentration of O3, the faster the rate of decomposition>
The only thing I can think of & am hoping you can answer is this. I have a (new) Luft pump that pushes air thru the ozonizer, from the ozonizer to a T fitting, one side goes to the skimmer cup the other side goes to the venturi outlet.
Originally before adding the ozonizer there was a tube that went from the skimmer cup to the venturi, this is to "self-clean" the venturi. There is a small hole in the cover for the skimmer cup for air to be pulled through the tube.. When I got the ozonizer set up I smelled a bit of ozone, I traced it to coming from that small hole. (I put a piece of paper towel over the hole & it floated off) So I put a piece of tape over the hole, since it was no longer pulling air in but air was being pushed out.
<Should work>
Do you think that somehow caused the fittings to break down?
<No... just exposure period>
It was suggested that I should replace the 3 fittings with stainless steel ($80 for these).
<A possibility. You need this/these or other O3 resistant fittings>
I hope you can help me figure this out before my husband makes me throw it away!!
thanks for any suggestions
<Yikes II! Bob Fenner>

My ORP drops with the application of Ozone 2/23/2010
Hi Guys,
<Hello Dean>
I appear to be having problems increasing ORP.
I have installed a Red Sea 'Aqua Zone 100 Plus' (with pump and air dryer) via an American Marine ORP Pinpoint controller to my new tank.
<Ok. A mid-range brand>
I routed the air/ozone line into my Deltec skimmer. I have calibrated the controller probe and believe everything was set up correctly. Regardless of the rate of ozone production or airflow the ORP value in the tank drops.
Initially I installed the equipment on my new 250 gallon system (with two day old synthetic salt water mix). The mV reading prior to adding ozone was 250 and after two hours the mV had dropped to 240. I borrowed half a gallon of 'old' water from my Nano tank, dropped in the probe, and pumped in ozone (at 100 mg/hr). Within minutes the mV reading had dropped from 230 to 200.
<Ok, are you talking about the readings as soon as you have set up the equipment? These can take a day or more to settle down>
Any suggestions would be much appreciated,
<That, or a faulty probe. I have used these same probes and found them to be a little unreliable. Two different ones, for example, giving different readings. If you are still getting the same readings in a couple of days you could test this probe against another, perhaps of a different make.>
Kind regards,
<And back!>

Ozonizer/Air Dryer Questions -- 02/09/10
<<Ciao Bella! (with my best Italian accent)'¦sorry 'couldn't resist [grin]>>
Hope you all are having a good day (evening)!
<<Not so bad thus far, thanks>>
Hoping you can help me with this set up.
<<Will try>>
I researched your site for Ozonizer setup but still have a few questions.
My set up is: Luft pump then 3' of standard air tubing
<<Mmm, you need to use 'ozone resistant' tubing. Aside from it rapidly deteriorating and cracking/leaking, the standard vinyl airline tubing reacts greatly with the ozone and depletes/reduces the output. There are several 'ozone resistant' materials to be found, but I find silicone tubing to work very well and at reasonable expense>>
going into a Taam 1200gm air dryer then a 3' section of airline tubing going to the Ozonizer then it comes out with 1/4" tubing section maybe 5' long that goes to a T fitting so that it connects to my LifeReef protein skimmer.
<<T-fitting'¦ Why? And again 'all tubing used needs to be 'ozone resistant'>>
I tested the air flow at the T connector but nothing was coming out. I bypassed the Taam air dryer & now there is air flow (Luft pump is on highest setting).
Do you think there is too much media in the Taam air dryer,
<<Not likely 'the Luft pump should be able to handle this easily 'do check if for a cracked diaphragm>>
or perhaps just too much tubing
<<Maybe 'always best to reduce this to the shortest 'run' possible>>
or I have something set up wrong?
<<Don't know but is another possibility. Any 'check-valves' on this line?>>
I also have a Milwaukee SMS510 controller that the Ozonizer is hooked up to.
<<Ah! This is the same one I use>>
My ORP was 220, after about 20 minutes then it suddenly dropped to 170 (the one minute I wasn't watching it!) then over maybe 10 minutes went steadily up to 212. I have the Ozonizer turned to its highest setting & have the ORP controller set at 400.
<<Okay 'I would give all a couple days to settle down/stabilize at this point>>
My nitrates are at 10, ammonia 0, nitrites 0. I am having some trouble keeping pH & ALK in the proper place but am thinking this ORP reading of 212 would explain that.
<<Maybe so, but 'did you check the probe? Don't just assume a new probe is 'accurate,' they should always be checked with a calibration fluid before, and periodically during, use>>
Calcium is always at 450 with no help from additives & magnesium stays about 1200.
<<The Calcium level may be linked to your Alkalinity issue. Have you read the 'marble analogy?' See here: http://www.wetwebmedia.com/calcalkmar.htm I would also boost the magnesium a bit for some wiggle-room if nothing else 'figure about 3x your Calcium reading>>
I am running the Ozonizer now without the air dryer since the low ORP rather shocked me,
<<Do check/validate the probe>>
not sure how long it takes to mess up an Ozonizer without the air dryer
<<Depends on the unit'¦ Using/not using an air-dryer is more of an efficacy issue, though cheaper units may well be malaffected in the long term re. I found removing and drying the Silica beads to be such a hassle that I run my unit without, but I have an 'Ozotech' unit that is actually designed to be run either way (the electrodes can be removed for periodic cleaning)>>
so I hope you all can tell me what's wrong?
<<Hard to say what may be blocking the dryer. Try blowing through it with your mouth 'and give it a good looking over, perhaps one of the Silica beads has fragmented and is blocking a connector>>
Thanks a bunch!
<<Be chatting! Eric Russell>>

Re: Ozonizer/Air Dryer Questions (and now nuisance algae too) -- 02/19/10
Hey Eric,
<<Hey Bella!>>
I thought I would wait to see how the ozonizer did before asking you a few more questions.
I have an Ozotech 150 ozonizer,
<<Ahh an excellent make>>
I still can't get air thru the Taam dryer even though I shortened the lines,
<<Hmm a 'reversed' check-valve maybe?>>
and I can blow air through it so it's not blocked,
the Luft pump is new and the diaphragm seems fine.
<<Must say I find it very odd that this pressure-rated air pump can't 'get through' the bead dryer>>
So for now I'll just clean the ozonizer.
<<Follow the manufacturer's instructions re and this will be fine. I have been doing some reading/research of late and it seems that the use of an air dryer, at least at a non-commercial level, may only be of 'nominal' benefit at best. This is based on some tests performed by Randy Holmes-Farley utilizing a single make/model of ozone generator 'so while interesting/thought provoking, is hardly conclusive. Still, cleaning the Ozotech every 1-3 months beats removing/drying silica beads a couple times a week>>
My ORP has settled down, staying right around 350 unless I add water etc.
<<Very good'¦ You could increase this somewhat by utilizing an ozone reactor as opposed to the skimmer (I've become convinced that a reactor is a much more efficient means of utilizing ozone in aquaria)'¦but this reading is fine>>
I should have told you I did calibrate the ORP meter before using it.
Also I do have ozone safe tubing; I just didn't make that clear.
<<Excellent 'thank you for the clarification>>
I am still adjusting my magnesium to get it to the correct level and have started adding baking soda to get the Alk up to par (Was in the low end of normal).
Question time: sorry for the length of it.
<<No worries>>
Tank is 95g high, 250W MH light with Phoenix Hex Arc bulb (2 months old), 125 lbs live sand, 175 lbs live rock, (tank is about 3 yrs old) 2 Vortech mp 10, 1 Maxi-Jet updated to 1200 gph, 1 Hydor 3, LifeReef protein skimmer w/500gph pump. 1 Firefish, 2 clown gobies, 1 maroon clown, 1 6-line wrasse, 1 Arabian wrasse, lots of Asterina starfish, snails, hermit crabs. Some SPS frags and LPS frags and a Maxima clam. My problem is algae,
<<Mmm oh so common>>
I have never gotten rid of diatom algae since I first set up the tank but through this website I have gotten it to where it just needs the glass cleaned a few times a week,
<<Ah hardly a 'problem' then>>
but right around Thanksgiving I started to get the green stuff.
<<Not talking about green-bean casserole I take>>
I couldn't place why till right around Christmas when I discovered that my R/O membrane needed replacing (letting 2ppm get past it) although it was only 3 months old.
<<Mmm'¦ It's not unusual for an RO membrane to 'allow' a small TDS reading. Most any membrane will have a less-than-100% rejection rate (and is why many reef hobbyists employ DI (deionization) in conjunction with RO)'¦with many of the 'better' ones rating at 98% rejection. And even this value can be hard to measure/quantify for the casual hobbyist. A good rule-of-thumb in my opinion is'¦ If the membrane is providing a minimum ten-fold rejection based on the TDS reading of the untreated source water, then it does not need replacement. In other words, if the TDS of your source water is 200ppm and the effluent from your RO unit reads 20ppm or less 'then all is fine re the membrane. In actuality I find the quality TFC membranes offered today will usually read less than this unless you live in an area like Bob where they are pumping 'liquid rock,' which can greatly shorten the useful life of the membrane (Do consider installing and utilizing a 'flush-unit' to increase the life of any membrane)>>
Got a silica test kit and tested the tank water and silica was at zero so I just continued with the weekly 15g water changes. Nitrates were and still are at 10,
<<Be sure to validate this test kit>>
ammonia 0, nitrites 0, phosphate 0, silica 0. I thought adding the ozonizer and improving the ORP would help,
<<Is of benefit>>
but no evidence of that yet, in fact the hair algae is growing,
<<But is not a panacea>>
and about 2 weeks ago I noticed some short green stiff algae starting in a few places and yesterday I noticed some of the red slime starting. I just don't get it.
<<Do you employ carbon to filter the skimmer effluent? I have dismissed its use in the past with most all these hobby-grade generators as unnecessary. Partly due to ozone having a very short half-life of a few seconds when applied to seawater, which means little to none should ever 'escape' the skimmer and sump to return to the display, and partly due to the low output of the hobby-grade generators. But I'm starting to think otherwise re the necessity to filter the effluent with carbon as there's more to it than just any residual O3 present'¦ The oxidizing effect that provides the benefits we want from utilizing ozone, also generates undesirable byproducts in seawater such as Bromate, Hypobromous Acid, etc'¦. Ozone is also quite effective apparently at converting Ammonia to Nitrate, which might explain your reading above re. All in all 'based on observations of my own system and further reading/research, I suggest you pass the effluent from your skimmer over carbon when employing ozone>>
There is so much flow in this tank now that I have to turn off the pumps in order for the fish to have some chance of getting the food. I feed several brands of pelleted food, and only give maybe 1/8 tsp. one time a day.
<<Mmm, I suggest a least a 'couple' small feedings a day. Starving/depriving your fishes is not the solution to algae issues 'in my humble opinion>>
Total water flow is 5220 gph + whatever from the skimmer return. Which exceeds the 20x flow that this website says you need (1900 gph for a 95g tank right??).
<<Indeed... Though 'need' is relative to the system and its inhabitants>>
There is so much flow that the algae is actually flowing sideways. I thought about adding a tang but this seems too small a tank for one, and it doesn't really address what's going wrong anyway.
<<Bingo 'need to determine the fuel source for the algae. But be aware it is not always possible or even practical to eliminate this (the other living organisms in your system require some measure of nitrogenous compounds for survival, and even to thrive). Many times the answer lies in creating/optimizing conditions for the algae to be 'outcompeted as in employing a lighted 'vegetable' refugium>>
I cannot add a refugium because the cabinet opening was only made big enough for a canister filter (which WWM said to take off)
<<I would employ the canister as a 'chemical' filter utilizing cut-up Poly-Filter. This quality media absorbs a wide range of organic and inorganic compounds 'and changes color to tell you when it has been exhausted>>
and the only other way to install one would involve cutting thru a wall and taking out floor to ceiling kitchen cabinets.
<<This is indeed unfortunate 'a refugium would certainly be of benefit>>
My husband would really freak then.
<<Don't wanna freak out hubby'¦>>
Seems like the harder I try the worse things get. Any suggestion?
<<Add a DI canister to your RO filtration, utilize carbon to filter the ozone treated skimmer effluent, and employ the canister filter with the Poly-Filter medium. Fighting nuisance algae is often a battle with many fronts>>
<<Happy to share'¦ Eric Russell>>

Ozonizer Question, set-up/op., and photo-acclimation of "corals" 1/14/10
Hi All !
<Hello Bella>
I was given a Ozotech 150 Ozonizer and no instructions. I know I need a air dryer (I'm in muggy MS.),
<I'm in cold MI.>
and a ORP meter or controller. I am looking at the Milwaukee line, but am unsure if I need the controller or the meter, there is no place on the Ozonizer to plug anything in, and I can't tell from the pictures of the controllers if there is a place that you are supposed to plug the Ozonizer into it.
<There is, the ozone generator plugs into the controller.>
Some quick stats before more questions!
95g reef tank (36"L X 24"D X 24" H)
0 ammo, 0 nitrites, 0 phosphates, 10 nitrates. PH 8.1 Alk 2.0 (API tests)
175 lbs live rock, 125 lbs live sand 1) False Lemonpeel Angel,
<Nice fish, have one myself going on three years.>
2) Clown Gobies, 1) Lawnmower Blenny 1) Maroon Clown, 1) Six Line Wrasse, 1) Arabian Pseudochromis, 1) Firefish. Assorted sps corals, assorted snails, hermit crabs etc. Filtration is live rock, sand & a LifeReef protein skimmer.
<Nice skimmer.>
10g. water changes weekly with r/o water (zero phos. nitrate etc.) & Oceanic salt.
Supplements Seachem reef advantage magnesium. Lighting is a Current SunPod HQI 250W/DE with a Phoenix hexarc blue 14000K (1 month old bulb) which to me is not blue at all.
<Yes, very little blue, but a good Kelvin temperature for reefkeeping.>
Bulb is about 11" from top of water.
My problem is that I get a pretty SPS coral & over a month they slowly lose color.. They are growing but new growth doesn't have the color it originally did.
<Are they colorful in your tank after you get them, or pretty in the dealer's tank before you take them home?>
I'm not sure if the corals lose their color because of the nitrates, the light being too high, the wrong bulb.
<May want to read here and linked files above.
Bulbs are confusing to buy! I started out with the Hamilton 14K but read such good reviews on the hexarc blue that I decided to give it a try but to me the color just looks bland.
<You may want to add an actinic lamp to give you that pop you are looking for.>
I also have a NextReef MR1 running with Chaeto
<Chaeto in a reactor?>
with a Current SmartPaq daylight/actinic bulb. I set that up a month ago because nitrates had been running around 20 (API test), didn't really think that would work, as it wasn't in a refugium, but it has doubled in size & the nitrates did go down by 10 points.
<Mmm, not clear, confusing. Which of the above did you set up, the reactor, the lighting, and what doubled in size, the Chaeto?
Thanks for your help
<You're welcome. James (Salty Dog)>
Re Ozonizer Question 1/15/10
Hi James (Salty Dog)
<Hello Bella. Let me ask you to please reply to the original thread. That way I can refresh my memory by reviewing.>
Thanks for such a quick reply!
<You're welcome.>
I set up the NextReef MR 1 with the Chaeto in the reactor with the Current SmartPaq daylight/actinic sitting on its side to light the height of the reactor. Yeah I know weird, but hey, sometimes you got to go with what you have!
I didn't think it would work but surprisingly it has, at least for now. I run the light 16 hours on & 8 off.
The lighting for the 95 tank I run for 10 hours. The corals are very nicely colored in the tank when I first get them. No pet stores here that carry corals so I have to order online. I have tried several ways to acclimate them to the light, starting them low & over 2 weeks slowly moving them to the area & water currents that they need, to just putting them right where they should be. Everyone of them slowly fades over about 4 weeks. The latest was a beautiful ORA red planet. Started out very deep pink with green at base, now is a pale pink. On the 10g water changes, I split it so it's 5g one day, wait 3 days & do the other 5g.
<I would do this all at once. You are removing a percentage of the first 5 gallons by way of dilution.>
I make up the water 48-72 hours in advance, making sure temp, ph, Alk, calcium, mag. are all the same as the tank. I also acclimate the corals according to your site so I know I have at least that part right. Any advice would be greatly welcomed.
<I'm thinking the Zooxanthellae in your corals are just reacting/adjusting to a different type light (intensity/Kelvin
temperature) than they were accustomed to. I say this because it is affecting all your corals and
not an individual coral. I do not have the original thread handily so I'm not sure what type of lighting
you were using, I'm thinking MH. You may want to add a true actinic lamp to your system to beef up the
blue end of the spectrum. Again, I wish you would have replied to the original thread.
Do read here and linked articles/FAQ's in the header regarding coral lighting.
If you are concerned about heat with an additional lamp, Ice Cap has a new LED product that looks very promising and is relatively inexpensive. See here.
Thanks again,
<You're welcome. James (Salty Dog)>

My ORP is too high 470-480 10/27/09
Hi, thank you for answering my previous questions. I added recently an ozonizer that ran for 2 days in my system and than I disconnected since my ORP is 470-480. Is it too high?
<Mmm, yes. I'd endeavour to keep it about 400... not more than 425>
if so, how should I lower it?
<? Is it adjustable in terms of output? Turn it down... Are you using a controller, a probe?>
For now, I disconnected the skimmer every night , is that a good idea?
Also I am using a skimmer rated for 3 times my volume system. Thank you
<Have given a pitch/presentation re O3/RedOx a few times this past year...
It's archived here:
and there's an article version, other pertinent FAQs files linked above.
Please peruse.
Bob Fenner>

Red Sea Ozonizer plus 100 Questions: Ozone Generator questions Not much information to go on. 9/1/2009
I recently purchase ozonizer.
<A worthy investment.>
I followed the instruction manual but I can't adjust Ozone Output level in mg/hr. its reading 0 and the red light is not on.
Running time 24 hours
ORP reading 307
ORP set point 357
<Sounds fine. are you SURE you have all of the knobs set correctly and the switch is set to OZONE and you have the ozone knob set to something greater than zero? Are you sure you do not have your ORP and set points crossed?>
air dryer still blue but notice slightly pink where air pump line
<You have air moving through it.>
You think I need to upgrade air pump?
<I have no idea what air pump you have on there.>
air flow low.
<Did you buy the recommended air pump?>
I have a ASM protein skimmer with Sedra pump. Where do I inject the ozonizer outlet
<If your skimmer does not have a separate ozone port, you will have to inject it into the main air inlet for the skimmer. You can inject the ozone off of a tee fitting to mix the ozone enriched air with regular air, or with a large enough air pump, you can hook the air inlet of the skimmer right to the ozone generator. Do realize that any connectors you use will be broken down by the ozone quickly. Fittings made of Kynar are extremely ozone resistant.>
please respond need a lot of help thank you.
<Have a read here: http://www.wetwebmedia.com/ozonefaqs.htm >

Phosphate resin material, and O3 intro. 5/5/09
Hi Bob,
You recently gave a great talk to our club(CMAS) in Maryland. The topic was ozone and ozone generators. Do you recommend hooking the outlet up to the protein skimmer?
<Yes I do. This is the best place>
If so does it have any effect on the plastics that make up the skimmer?
<It should not... almost all skimmers are made with "good enough" materials to preclude such>
I have two air input tubes. Do you feed it directly into one of the tubes?
<Yes... whichever leads into the main mixing area, the contact chamber, of your skimmer>
Do you think it is possible to run two tanks off of the same unit. I am looking at the Ozotech unit?
<Mmm... I do think this might be possible, though metering could prove problematical>
I also asked you about phosphate removal and you said that the best material now is lamison (not sure of the spelling). Could you please give me the correct name and who makes this product?
<Yes. Lanthanide>
Thanks again for the great presentation.
Mark Strohman
<Welcome Mark. Bob Fenner>

Question About Ozonizer -- 04/22/09
Dear Crew,
<<Hey there Andy>>
Hope all is well with you.
<<Hmm, how would my buddy Bob put this? I'm still vertical 'I'm still looking 'down' at the grass'¦ So yes, I suppose all is well!>>
I had the pleasure of meeting Bob in person this past weekend
<<Ah! Quite the character, ain't he?>>
--and I even got him to sign my copy of TCA!
<<I have a signed copy as well (waiting for the value to escalate so I can auction it off as Sotheby's and retire [grin])>>
His pitch was about the value of using ozone in marine aquaria.
<<Ah yes 'I too am a proponent>>
Unfortunately for my bank account, it doesn't take much to get me interested in pursuing a new and useful gadget.
<<Mmm, yes 'and a little extra money spent here can mean much>>
Until I heard Bob speak, I hadn't given any thought to using ozone.
<<I see>>
It's not something that's talked about much in the normal circles, at least as far as I can tell.
<<Hmm'¦ I don't know that that's it so much as it is just so readily dismissed because folks don't understand it>>
In any event, I started snooping around the e-tailer sites to get a feel for what is involved and what kind of equipment I would need.
<<That's a start 'how about some research/reading up on the process of producing ozone itself and the effects re?>>
Based on Bob's statements, I figured that, for my 90 gallon reef (30 gallon refugium), something in the 50 mg/hour range would be a good choice.
<<There are lots of variables that can determine the size unit needed aside from the volume of the system (e.g. - bio-load, method of introduction, efficiency of the unit) But even with just the info here, I would recommend a unit at least twice this size 'especially if one of the 'cheaper' hobby units. I run a very good quality, very efficient 300mg/hr Ozotech unit on my 500g (en toto) system and have never had the ORP exceed 370mV>>
As luck would have it, I happened to see an advertisement today from a fellow hobbyist who was selling a new-in-box Red Sea AquaZone Deluxe 100 mg/hour (Ozonizer/Controller with ORP probe and 250cc dryer) for $250 plus shipping.
<<I have heard mixed reviews on this brand, though I think I recall Anthony once gave these units a thumbs-up 'and at least it is a 100mg unit>>
At least from a price standpoint, that is a great deal considering this unit retails for $350 (if you catch it on sale).
<<Do consider the Ozotech units'¦ For the $250 you're thinking of spending you can get a much better ozone generator than the Red Sea units, in my opinion. The Ozotech units are 'Cold Spark' corona discharge units that are field serviceable. This means that not only can the discharge cells be replaced should it ever become necessary (not for a very long time with care/cleaning), but you can operate the units WITHOUT a dryer as long as you clean the discharge cells a few times a year. And believe me, unless you are going to fork out the money for an 'electric' dryer unit, you will spend much time/grow quite weary of recharging the silica-beads (necessary every few days, in my experience) of those 'standard' dryer units. You will still need to get a controller (Milwaukee has one for about a C-note), but the quality and longevity of the Ozotech unit will more than make up for the extra expense>>
I would rather have a 50 mg/hour unit to minimize the risk of disaster, but this deal is too good.
<<Even without the controller, a 100mg unit would pose little risk if any here I think 'but with a controller, you really have nothing to fear re the size of the unit>>
So far as I can tell, there aren't many options out there for Ozonizers
<<A few'¦ Red Sea as you've noted 'with Sanders and Ozotech both providing better units>>
and it appears that the Red Sea line is fairly popular,
<<'¦'cause it's inexpensive, and maybe not as durable in/around a humid environment as it should be. Though to be fair better than nuttin, I guess>>
so I'm hoping that someone at WWM has some experience with it and can share his/her experiences/thoughts on it?
Thanks, as always.
<<Happy to share'¦ EricR>

Re: Question About Ozonizer - 04/23/09
<<Hi Andy>>
Thanks for the response.
<<Quite welcome>>
The reason I noted the 50 mg/hour unit was that Bob specifically admonished us to get the smallest unit necessary, because Murphy's Law . . . Anything that can go wrong, will go wrong.
<<I don't disagree 'but the keyword here is 'necessary''¦ I believe it is possible to obtain 'too small' a unit for one's system and thus not fully realize the benefits of employing ozone. All the more reason to do your research (hopefully from multiple sources) and make an informed decision>>
For example, I have a 4 year old . . . I can see him playing with the knobs'¦ Anyway, I have a follow-up question, if you don't mind.
<<Not at all>>
I run an AquaC EV-180, and the manual suggests using ozone only for 3 or 4 days a month because of its impact on the efficiency of the protein skimmer.
<<Mmm'¦ I do disagree. The addition of ozone may well impact the skimmate output due to its effect/the breaking of molecular bonds on some elements which may make them more susceptible to scavenging by other means (e.g. -- chemical filtration)'¦but I hardly think it makes the/any skimmer less 'efficient' than it was to begin with>>
<If I may kibitz, I agree with EricR here... run your ozonizer continuously. RMF>
The manual goes on to say that because ozone destroys/removes dissolved organics, your skimmer will have less to skim. Now, I'm no scientist but it seems to me that whether you remove organics through ozone or through a skimmer really makes no difference.
<<Indeed (though to be clear, I advocate using both methods in unison)'¦ And the two methods do also share some benefits such as improved oxygen and ORP levels. But in my opinion 'nothing matches the 'water clarity' obtained by utilizing ozone>>
The important thing is to remove organics. Do you know if one loses something by running both a skimmer and an ozonizer 24/7 that you wouldn't lose if you ran only the skimmer 24/7?
<<I fee both have benefit and I do run both 24/7 on my own system 'as I suggest you do>>
Thanks again.
<<Always welcome'¦ Eric Russell>>

More Questions About Ozone Use - 04/30/09
Dear Eric,
<<Hiya Andy>>
Sorry to bother you again, but I have a few follow up questions regarding ozone.
<<No problem 'and not a bother>>
First, I did buy the Red Sea Aquazone Deluxe.
I know you believe there are better units out there, and I don't disagree, but I thought a brand new 100 mg/hr unit with all the fixin's for $200 less than retail was a good start for me.
<<Sounds fine (after all 'it is 'your' money)>>
Now that that's out of the way . . . I have an AquaC EV-180 without the special fitting and I corresponded with AquaC about how to run the ozone through the skimmer. As instructed, I drilled a hole next to the air intake, inserted silicone tubing in the hole and sealed it with silicone gel.
<<'¦gel? As in 'sealant' I presume'¦>>
Thinking ahead, which is something I don't always do, I decided to affix only a small length of tubing to the skimmer, which I connected, using a brass barb, to the longer piece that attaches to the ozonizer so I can disconnect and service the skimmer.
<<Mmm, it may be a small risk but I would replace the brass barb fitting with a plastic barb fitting (for fear of liberating copper ions via the ozone), or better yet, a JACO connector>>
First, although the unit was unused and the manual says the Red Sea ORP probe is pre-calibrated to work with the controller,
<<Always best to calibrate any such new equipment/probes>>
I want to confirm that my probe is in fact calibrated.
<<You can only do this with a calibration solution of known value>>
My ORP reading is 190, but I do a 15% water change (RO/DI) every two weeks, employ a good skimmer that I service regularly, have a 30g refugium with Chaetomorpha, have a shallow substrate bed (1/2" or less), and have a pretty light bioload, so I'm skeptical of a reading that low.
<<Hmm does sound/seem 'low and I hate to say 'but maybe why this unit was sold/sold so cheaply?>>
Right now, I have the probe mounted in my sump where the water enters from the overflow, so there is a lot of circulation/flow there, but I did notice that when I had the probe in my tank, the ORP was measuring at about 230.
<<Readings can fluctuate quickly and are probably influenced by the position/location of the probe>>
The manual says that you can get different ORP readings at different locations and to search around,
but it also says to place the probe in a dark place, like the sump, to avoid fouling.
<<It may require more maintenance 'but I prefer to keep my probe in the tank (near those affected most)>>
Maybe the reading is correct, but maybe not . . . Do you know if I can just use any ORP probe calibration fluid?
<<Any fluid with a known value in mV, yes>>
Second, and I'm sure this varies with conditions/Ozonizers,
<<And environments/tanks>>
but how long does it generally take to see a change in ORP once you start using ozone?
<<As long as the unit is large/efficient enough to make a difference 'within a day or two for sure>>
Third, is it absolutely essential (for safety) to filter the air exiting the skimmer with activated carbon to eliminate any excess ozone?
<<Not in my opinion (I don't do this). The molecular interaction/action of the skimmer itself will do much to remove/use the ozone 'and residual ozone is not much if any of a threat with most of these hobby units if utilized/installed correctly, in my opinion. But do consult others re and decide what you feel comfortable with>>
When Bob F spoke about this, he basically stated (I'm paraphrasing, and hoping I got it right) that, given the small amount of ozone we employ in aquaria and given that ozone so readily dissipates/metabolizes/whatever, this really isn't a concern,
but if you want to be 100% safe, go ahead and filter the air.
I can definitely smell some ozone in the air when I'm around my tank--nothing overpowering or anything, but it's there. I've asked the good people at AquaC, but I'm scratching my head as to how I might go about filtering the air leaving the water exit valve (which, other than the collection cup drain, is the only place that ozone can escape)--the EV-180 manual says not to restrict the flow of this water. If I stick a filter bag full of carbon over the exit valve, the flow is going to be restricted. Although the restriction may be small at first, I anticipate that the bag will foul over time and the restriction will become more significant.
<<Agreed'¦ But you can simply place a bag of carbon in the sump 'under' where the water falls from the skimmer 'and another atop the collection cup vent holes (if it has such). I really don't think you have much to fear here 'but as stated, do what 'you' are comfortable with>>
Thanks again for all of your help.
<<Always welcome'¦ EricR>>

Re: More Questions About Ozone Use - 05/01/09
Thanks for all your replies!
<<Always welcome>>
Yes, I meant silicone sealant--was drawing a blank when I was typing.
<<Happens to me too>>
I don't intend to keep the brass barb--I chose that over nylon (which is all that my crappy stores carry here) based on my research of what materials work with ozone (brass was given a B, while a nylon was F).
<<Wouldn't worry re the nylon fittings can be easily/inexpensively changed out as necessary>>
I am going to try to find a glass barb or something similarly un-phased by ozone.
<<Not necessary 'the nylon or plastic fittings (is what came with my unit) will last/serve fine>>
As for the AquaZone, who knows if it was dropped off a roof, but it truly does look brand spanking new--the seller swore up and down that it has never seen water. We'll see.
<<Ah yes 'it is likely to be either just a bad probe, or a unit in need of calibration>>
Andy Bulgin
<<Eric Russell>>

AquaC's Reply/Solution for Filtering Residual Ozone from their EV-180 Skimmer -- 04/30/09
Dear Eric,
<<Hi Andy>>
I e-mailed you earlier today with three questions, one of them involved the need to use activated carbon to remove ozone from the air/water leaving my AquaC EV-180.
<<Ah yes 'and I've just sent that reply>>
AquaC got back to me and provided me with some interesting info, which I thought I'd share with all.
<<Excellent 'thank you for this>>
See below/attached (I'm still interested in confirming Bob's statement that excess ozone in the air isn't really a concern). Not only does AquaC provide great customer service, but I love how the company gives you DIY solutions rather than just pushing its specialty products on you.
<<Jason and Steve do truly excel at customer service. Eric Russell>>
--- On Wed, 4/29/09, Steve - AquaC Customer Service
<steve@proteinskimmer.com> wrote:
From: Steve - AquaC Customer Service <steve@proteinskimmer.com>
Subject: Re: Follow Up Question about EV-180
Date: Wednesday, April 29, 2009, 1:35 PM
Hi Andy,
The air exiting the collection cup can be filtered by using one of our Auto Waste Containers, which features a carbon chamber on the air exhaust. An easy DIY solution would be to run a tube from the collection cup drain into a cup or chamber filled with carbon. This requires frequent emptying of the collection cup, since skimmate cannot be allowed to drain into the carbon container. We recommend using a larger size carbon, which will not pack as tightly and restrict airflow out of the skimmer. To filter ozone out of the water exiting the skimmer, you'll need to set up another carbon container for the return water to flow through. Water needs to be able to flow freely from the skimmer, so the water needs to pour out of the skimmer into the container. Something similar to a filter sock setup can be used (see attached diagram).
Thanks again, and let me know if you have any other questions!
Steve Prince
Customer Service Manager
AquaC, Inc.
7949 Stromesa Ct., Ste. E
San Diego, CA 92126
858-689-1121 phone
858-564-3419 fax
visit us online at...
www.proteinskimmer.com < http://www.proteinskimmer.com/>

R2: More Questions About Ozone Use - 05/03/09
Okay, Eric, I am a complete moron.
I didn't realize that you have to take the plastic black cap off the end of the electrode!
D'oh! The cap has a hole in it and a white plastic insert, and the Red Sea instructions do not clearly state that the cap should be removed. I thought it odd that the cap should stay on. Oy!
<<Hee-hee! Sometimes the simplest of things'¦'¦'¦'¦>>
Now I am getting good readings.
Andy Bulgin
<<Excellent my friend 'though 'I' would still stick the probe in some calibration fluid just for my own 'knowing.' Cheers mate'¦ Eric Russell>>

Question about hyposalinity and ORP 12/17/08 Hey guys and gals, it's been a while since I've had a good question to ask :-) <Longer for me!> I run an ORP controller and generator on my 210g saltwater tank. I keep the ORP level around 375. <Good> My question is this. if I take my tank down to hyposalinity levels, say 1.009, will I still want my ORP to be 375 or does it differ when the salinity drops? <Mmm, good question (as am given to contemplate how to formulate a response). I would purposely lower my setting here... to something in the 330-350 mV range... 375 is too high to "risk" at lower spg. 400 is about the highest absolute maximum I advise period.> Thanks for the help you guys offer, it's great! Grant <Welcome my friend. Bob Fenner>

Re: Ozone questions -- 10/02/08 Hi again Bob, <David> I hope you had a great time in Hawaii and all is well. I have started a small travel budget so next year I won't miss MACNA. It was disappointing to have missed it this year especially once I saw all the speakers that were on the agenda. <Was a hoot, informative> I have another question on Ozone. I have set up another ozone generator on the broodstock system now and am really enjoying the clarity of the water. <And much more... better health, growth of your livestock...> I have controllers set up on both systems and the ORP set to 300mv. I have noticed a slight ozone smell in the room occasionally when I come in to feed the fish. I usually leave the door open for a minute or two and the smell quickly goes away. My question is should I be concerned. <Mmm, I would not be> Both systems are injecting directly in to the skimmer and I am guessing the smell is from the outgassing of the ozone in the skimmer cup?? <More like interactions therein> All fish seem healthy and I haven't noticed any real change in behavior except my Ocellaris clowns quit spawning but 2 other pairs have started so I have 4 spawning now!! <They do "come and go" as you know> Is there any tests that you think I should perform to check the system? <Mmm, other than routine ones for pH, alkaline reserve... and possibly spot-checking RedOx potential... Not IMO> I also just recently purchased an Nitrate reactor from a club member that just recently tore his large tank down. I figured I could use it in the grow out system to help reduce nitrates. <Much we could discuss here... in actual process, culture facilities "as yours" don't really have much to gain/fear from dealing with NO3...> Randy Reed is coming into town in a couple of weeks to speak to our club. The meeting this month will be at my house so I have been doing a lot of extra cleaning in preparation <Ahh, is a fine fellow. Seems knowledgeable, forthright, friendly> I am going to start a photo gallery on the wall in the clown house of all the speakers I can get to see it. You were the first. I wanted to send down a photo to you if you would sign it and send it back then I can have it posted before the meeting. Is that OK with you? <Can you Photoshop me ala the chubby (but talented) singer of the rock band "Heart" to make me a bit thinner? Heeeeeee!> Well that is all for now. Take care, Dave Durr <Will do. BobF>

Ozone, ap. Good morning crew, <Vincent> I have a question that I can't seem to find on your FAQ or other forums. The question is "Can I add ozone to a hang-on skimmer through an airstone?" <Mmm, yes> I have a hang-on Aqua C Remora skimmer with surface prefilter box. I am planning to tap the side of the skimmer. Inject ozone through a hose via an airstone at the bottom of the skimmer. I modify the skimmate collector cover with larger hole to allow placement of carbon. <Likely unnecessary...> I have placed carbon into the prefilter box where the return water of the skimmer exits. Will this method decrease the skimming capacity of the skimmer. Regards Vincent <Read here: http://wetwebmedia.com/redox.htm and the linked files above. Bob Fenner>

Re: Ozone, ap. 9/20/08 Thanks Bob for the quick reply. What time zone does the crew at WetWebMedia run on? It is lunch time here. We are on Eastern time. <Mmm, there are folks all over the U.S.... but also in Germany, the U.K. and China...> Do you think the airstone will reduce the efficiency of the skimmer? <Mmm, no. Au contraire! It will greatly improve it... as you'll soon see> I ask because the bubbles of the airstone are not as fine as that produce by the skimmer. I don't want to improve one parameter at the expense of another. <No worries... and do read where you were referred to... If it were me, I'd skip the airstone and rig up the O3 to be just entrained into the injection system as is...> Thank you in advance for your valuable advice. Vincent <Certainly welcome. BobF>

Ozone Flow-Rate Question -- 04/23/08 Hello Crew, <<Hiya Mitch>> I just got an Ozotech ozonizer, <<An excellent choice/brand and piece of gear>> as well as an ORP monitor/controller. My question is this: I will be hooking the ozonizer to my skimmer, which is an E.T.S.S. The skimmer will be pulling the ozone through its air intake, and I want to know if I should get a Gas meter/regulator to control the amount of ozone which is pulled through the skimmer. <<Mmm, nope not necessary or even desired in my opinion>> Not sure what other ozone users do here. <<The easiest way to 'regulate' the ozone going to your tank is via the ORP monitor/controller you purchased. Once the set-point is reached (something between 350mV-390mV is suggested) the controller will shutdown the unit until the ORP falls again below the set-point. My own Ozotech unit has a dial adjustment (voltage regulator) that controls the 'amount' of ozone produced by the unit which provides an even more finite control when coupled with the ORP controller>> Also - I will have the output water flowing over/through carbon, but should I have carbon anywhere else in the setup? <<Sure, as a general chemical filtrant for the system 'but not as a necessity from utilizing the ozone generator>> Thanks for your thoughts.... Mitch <<Hope they help. EricR>>

Ozone, English, ap. 4/22/08 Hi guys I was hoping that you would be able to help me out with some info if that's ok. I currently run an eco system i.e. miracle mud its is running very well ,but I would like to introduce the use of ozone to it, I have a sander 25mg ozone unit correct hosing ceramic air stone and algard pump linked up to use but due to the fact I have no skimmer <I would get, use one> I am looking for a safe way to introduce it to my system through my sump via a ozone reactor if there is such a thing. could you help me out here thank you . reeferdude <25 mg/h is not going to hurt anything unless this is a tiny volume. Bob Fenner>

Batfish/Health/Systems And An Ozone ap. Question 3/13/08 Hi! I've had a Pinnatas Batfish for about 5 months - the front of his top fin is starting to erode. It had a white cotton like spot that is gone but now the area is starting to show signs of erosion. Water quality PH is 8.1, nitrate 0, ammonia 0, salinity 1.020. He seems to be happy, he eats shrimp soaked in VitaChem. He is in a 60 gallon Hexagon tank with a Marine Beta and a few blood shrimp. Are there any other nutritional supplements or foods I could use. Do you have any advice on how I can help him as he is such a delicate fish? <You're first question has already been answered and posted. See here. Batfish/Health/Systems 3/4/08 Hi! <Hi James. Always liked that name.> I've had a Pinnatus Batfish for about 5 months - the front of his top fin is starting to erode. It had a white cotton like spot that is gone but now the area is starting to show signs of erosion. Water quality pH is 8.1, nitrate 0, ammonia 0, salinity 1.020. He seems to be happy, he eats shrimp soaked in VitaChem. <Need a much more varied diet than what you offer.> He is in a 60 gallon Hexagon tank with a Marine Beta and a few Blood Shrimp. <I'm surprised the shrimp are still alive with the Comet for company. Tank is much too small for either of these fish. Offers very little swimming room.> Are there any other nutritional supplements or foods I could use. Do you have any advice on how I can help him as he is such a delicate fish? <Bi-monthly water changes, a good diet, and more room. As for foods, Mysis could be tried along with Ocean Nutrition's line of foods. New Spectrum pellets have been rated quite high as far as nutrition goes. Continue using the VitaChem or Selcon, does help. Do read here for more info on the Batfish. http://www.wetwebmedia.com/spadfsh.htm Thanks for your help. <You're welcome. James (Salty Dog)> Jim Hoffman I have another question regarding using an ozone generator in my reef tank. Is it normal for the hoses to deteriorate after having it filtered through carbon? Will it deteriorate equipment like power heads and wiring for the protein skimmer and heater in that section of the sump that isn't filtered through carbon yet? <It could, but not enough info presented. How are you administering the ozone? If through a protein skimmer, does the skimmer have a place to filter out escaping ozone gas? Do read FAQ's here on ozone installation/application.> Thanks for your help. <You're welcome. James (Salty Dog)> Jim

Ozone: how toxic is it really? 3/5/08 Hey guys, <Craig> Thanks for the great resource! <Welcome> My question regards some unresolved issues I have regarding the use of Ozone. I have a 120 gallon reef tank, with a 55 gallon sump. I have a few hundred pounds of live rock, and probably about 120 gallons of system volume. I have purchased a more-zon 30 Ozone generator that has a 30mg/h capacity. From what I have read this will provide my tank with a level of Ozone somewhat below that recommended for my system size. <Correct... 30 mg/h will not require any measuring, meter gear whatsoever> My plan is to inject the Ozone into my Aqua-medic TurboFlotor Multi SL. I've contacted Aqua-medic and they informed me that this protein skimmer is ozone safe, plastic-wise. I will not be pumping the Ozone in with a pump, since this type of skimmer sucks air, and as outlined in the Aqua-medic manual for their Ozone generator, the unit will provide the proper suction for the intake of the Ozone. I will be using an ORP controller to ensure that I do not exceed the recommended ORP values. Here comes my question: In some of your articles and FAQs it is advised that the effluent of the protein skimmer MUST be filtered over granular activated carbon (GAC). Other articles do not seem to stress this. Interestingly, the Aqua-medic manual for their Ozone generator, does not suggest doing this. <Not necessary here, I agree> Additionally, so as not to poison ones family, it is often advised that the gas that leaves the skimmer, also be filtered by GAC to filter the ozone from it. Even worse, I had a conversation with a representative at Aqua-medic who advised me that: "You do need to use carbon whenever you are using ozone" <Perhaps a statement to avoid liability> So... should I construct some kind of special cover to filter the vented gas, and some kind of box of GAC to filter the skimmer effluent? <Something could be fashioned to sit on top, between the collector and its cover... more for smell than ozone reduction> How worried should I be about poisoning my tank/family??? <Not at all... much more danger from household cleaners, aerosols, CO2, Radon trapped in the house...> I'm pretty mixed up by all the info and differing opinions that I've found. My goal is to improve water clarity and to improve the efficiency of my protein skimmer. Any help would be great! Thanks, Craig <There are 03 meters... You won't be able to measure any in the house... Bob Fenner>

Re: Ozone: how toxic is it really? - 3/5/08 Thanks so much for the reply. Just to follow up: Perhaps I increased the Ozone dose to a 100 mg/h or 200 mg/h, to the point that I needed to use an ORP controller. What benefits would using Ozone this aggressively give me, versus the water clarity effects that can be achieved at much lesser doses? Thanks, Craig <Posted: http://wetwebmedia.com/redoxrat.htm and the linked files above. BobF>

Ozone without a Skimmer 2/13/08 Is it possible to hook up a ozonizer to my salt water aquarium without a protein skimmer? If so how ? <Yes it is, you can buy or make an ozone reactor. Google the term and you will find a wealth of information on this. The link below does a good job of explaining the difference and how to implement. Scott V.> http://reefkeeping.com/issues/2006-04/rhf/index.php

Ozone Generator and ORP Monitor Questions -- 02/12/08 Hello crew, <<Howzit, Dave!>> I just purchased a Poseidon ozonizer from Ozotech. <Ah! A great piece of gear'¦ I use their OZ4PC10-V/SW 300 mg-hr ozone generator on my 500g (en toto) reef system. This brand is more costly than the 'usual' hobby generators, but also better built/more efficient/longer-lasting in my opinion. I think I recall Anthony C. commenting on having/using an Ozotech unit for ten years or more now>> I also bought a Hanna ORP/PH combo monitor. <<You may or may not 'need' a controller depending on the size of the system, bioload, etc'¦. But do consider the Milwaukee ORP controller. For not much more than a C-note (sometimes less, depending), you can constantly monitor 'and' control the output of the generator>> My first ORP test with this new instrument gave me a reading of 208mv. I understand this is somewhat low. <<Maybe 'depends on what was 'going on' prior to testing (e.g. -- feeding). But as a general rule, yes, an average ORP reading between about 330mv and 400mv is desired. You can go a bit higher (max 450mv), but I don't see the need to 'push the limit' here 'much like with Calcium and Alkalinity levels. Better to reach for a more easily obtainable/stable level within the acceptable limits>> So I turned on my ozonizer to try to bring my levels up. I decided to inject about 100mg/hr. It is my assumption that my ORP levels should have began to climb. <<But not quickly 'will need time to 'work'>> I took several readings over a 4 hour period and nothing changed. <<I would give the unit a couple days to begin to affect a change>> So I decided to crank my ozonizer up to the max level, and tested my parameters once again after about 45 minutes. Although my ORP level rose to 216mv, I still thought that this was not a significant change for the amount of ozone administered. <<Patience, Grasshopper>> So I turned the ozonizer back down to appropriate levels (80-100mg), and decided to give you guys a stab at my predicament. My thoughts and questions are; should I just monitor my ORP readings and give them more time? <<Indeed>> Is there any way to check and see if my monitor is giving appropriate readings? <<Yes'¦ Calibration fluids can be obtained online>> I'm just concerned about the low reading because I consider myself fairly conscientious and my husbandry practices are up to par. <<Perhaps it is best here if you stop use of the ozone generator and validate the efficacy of the monitor/probe>> Here is my systems layout: 90 gallon AGA, Mega-Flow. AGA model 3 wet dry, with bio-balls removed, instead I'm running 3x Chemi-pure Elites in the bio-balls place. ASM G-3 skimmer, where I'm administering the ozone. 22 gallon DIY refugium, with a 7 inch DSB, lit by 2x40w PC's. The refugium contains Chaetomorpha, and Pom-Pom Xenias. <<Ah an 'animal' filter then 'neat!>> My display is illuminated by 8 T5's with 4 18k's, 2 10k's, and 2 actinic bulbs. <<Hmm this is likely too much 'blue.' Your corals will do better with more bulbs closer to full-spectrum wave-lengths>> My tank's inhabitants are the following: 1-4in Kole Tang 1-4in Fox Face Lo 1-3in Coral Beauty 2- Cleaner Gobies 1- Mandarin 1-4in Derasa 1-Long-spined Urchin 1-Cleaner shrimp 1-Peppermint Shrimp 10-Astrea snails 10-Assorted Hermits It contains about 100lbs of live rock, and has a 1 inch sand bed. It also contains a couple (2 LPS corals) and 5 SPS frags. I do 10 gallon water changes every week with RO water, and Reef Crystals. I add nothing else except food twice a day. My basic parameters are good, no detectable ammonia, nitrite, or nitrate. SG 1.026, Calcium and Alkalinity levels are within range, and undetectable phosphate. Whew.... I hope that covers it. Any help or suggestions would be greatly appreciated!! <<I do think the ozone generator should have a greater effect than you have witnessed thus far. Verify the accuracy of the monitor, then start out slow and give the unit a couple days between adjustments>> Thanks, Dave Kansas City, MO. <<Happy to share. Eric Russell 'Columbia, SC>> PS. Still waiting for VOL. 2 Reef Fishes! :) <<Hee-hee! So is Bob!... ER>> <I'll say! RMF... waiting for help, folks who want to "make it happen"... anytime>

Ozone through overflow 1/17/08 Hi, <Jason> I have an idea for adding ozone to my system. Sorry if this e-mail is long, I want to make sure it's clear and my thought process is correct. <Good> I am just starting with ozone and have been doing a lot of reading (all your FAQs, ReefKeeping magazine, etc). From what I understand, ozone is effective when it is allowed to be in contact with the water then discharged over activated carbon (is that latter statement controversial?). <Mmm, no... at least not by way of my definition of the term/qualifier. Generally carbon exposure is unnecessary, but better to shy on the end of caution... and GAC use in captive aquatics does have merit period...> Injecting it through a skimmer or an ozone reactor allows the water to effectively dissolve the ozone. Randy Holmes-Farley in ReefKeeping Magazine described a DIY reactor made from tubing. <A worthy writer in my estimation> This got me thinking about other ways to inject ozone. In my tank, I have a built-in overflow with a Stockman standpipe (similar to the Durso standpipe). It submerges the water intake so there is no gurgling sound. The top of the standpipe is covered except for an air hole(s) to prevent siphoning. The bottom dumps into my sump. <I am familiar> My intuition so far indicates this may be a natural place to mix ozone, at least as well as a skimmer. Here is my thinking: stick an air line tube connected to the ozone generator down the top of the standpipe. Ozone goes in through the tube; the falling water will suck in the ozonated air a la venturi. <Mmm, something similar... simple entraining> In the standpipe, it will mix with incoming water and eventually exit the pipe in the first chamber of my sump. From there, I can place carbon in the baffles between the first and second chambers of my sump, or in a bag at the bottom of the standpipe. <If you'd like> Another thought is to inject the ozone in the overflow box instead of the standpipe. Say, using an air stone at the bottom of the overflow box. I haven't read much about using an air stone for adding ozone. The worry here is that the ozone will mostly vent out the top of the overflow instead of mixing in the water. But it's got about 2 gallons of water to get through, which is more than my 1 gallon skimmer. Any thoughts on these setups? <Mmm, yes... I doubt that any appreciable O3 will "exit" from any of these entry points, or distal from them... dependent of course on your source/generator... It will be something that makes a few hundred milligrams of ozone per hour I take it> My first concern is potential deterioration of some important part of the overflow or standpipe, like a bulkhead seal. Along this pathway I have PVC parts, the bulkhead and seal, a union, and a gate valve. <Possibly... though this will be minor very likely... years of use to see any deterioration> Let me know what you think! Thanks, Jason <I would still introduce the O3 into a skimmer... Bob Fenner>

Ozonizer/UV/Refugiums -- 11/27/07 I have read a lot of the FAQ's on your site regarding Ozonizers, but still I am confused and have questions, <<Okay>> I thank you in advance for your time. <<I'm happy to assist>> I have a 75 gallon tank, 70 lbs. of live rock, 20 gallon wet/dry sump (All Glass Mega-Flow 3), Coralife 65 gallon (needle wheel) super skimmer in sump, some corals and 20 fish <<This is a lot for this size tank...I hope they are mostly small...>> and some of these fish rely on this algae as a source of food. <<...?>> My bi-color blenny is steady working on the algae on the glass as well as my flame & coal beauty and not to mention the crabs and snails, wouldn't an ozonizer or UV sterilizer take away this natural food source? <<Possibly, though the Ozonizer more likely than the UV Sterilizer ...as a function of improved water quality. But the algae can be easily/readily supplemented through feedings, and in my opinion, the addition of an Ozonizer would far outweigh this perceived downside>> Also the mandarin and 6-line wrasses are always looking for pods, <<Normal behavior>> I think my system is not producing enough pods, <<Indeed...the tank is hardly large enough to support the Mandarin, alone...which is likely being out-competed by the wrasse for the available food supply>> would this be hurt by UV or ozonizer? <<Not appreciably... The UV will affect bacteria, mostly (which I don't recommend if you keep corals, which may feed on these)...and the Ozonizer, if correctly employed with the skimmer, should only affect that which was doomed/bound for removal from the system already>> My water does not look really clean, seems there is always a lot of small particles floating around, I have tried a number of different filters and set ups, have tried taking out the bio balls and there isn't much change. <<Removal of the particulates will require some type of 'mechanical' filtration. This can be in the form of a canister filter, adding filter floss to the overflow intake or a filter sock to the outflow pipe...with all requiring cleaning/replacement on 'at the least' a weekly basis>> I have thought about making sump into a refugium, what is the best way to configure my current sump and convert it to a refugium? <<Lots of ways this can be accomplished, It can be as simple or as complex as you want to make it. Do have a look through our wealth of info beginning here (http://www.wetwebmedia.com/refugium.htm), continue among the linked files in blue at the top of the pages and then return with more 'specific' questions if you wish>> Do you recommend this, if so, please advise best configuration/set up? <<The addition of a refugium is of benefit. My preference is to utilize separate vessels for the sump and refugium, but many hobbyists can/do incorporate the two together. For simple 'pod' production, an unlit refugium with a shallow and coarse substrate (1-inch deep of 3-5 mm grain size) with some live rock rubble will suffice. Keep in mind that to maximize populations, the critters in the refugium will require periodic feedings (a few shrimp pellets every couple days is sufficient in my experience)>> I also have a sulfur Denitrator and it has kept my nitrates at almost zero, but for some reason my corals and invertebrates have slowly died off. <<Are you saying there is a correlation here?>> I had already started losing my corals when I installed the sulfur Denitrator, my nitrates were around 40 <<Mmm...>> and now I am consistently 0-5, is there any side affects by using this and what are your thoughts on the sulfur Denitrator? <<I have no direct experience with this gear but have heard testimony to its effectiveness. If the Denitrator has been correctly employed/maintained I doubt it is the cause of your coral's demise. The corals/inverts may have already been severely malaffected by the high Nitrate levels and simply never recovered...or...there may be environmental issues/other issues of water quality at play here>> I believe we could have introduced copper from transferring fish from the aquarium store; some of their water had gotten into our aquarium. <<Not likely in sufficient quantity to be of concern>> Does the ozonizer take out the copper? <<No...add some chemical filtration (carbon/Poly-Filter) if this is a concern. To gain a better understanding of Ozone and its uses/benefits, please read this three part article by Randy Holmes-Farley on Ozone use and its application to marine aquariums(part-1 http://reefkeeping.com/issues/2006-03/rhf/index.php), (part-2 http://reefkeeping.com/issues/2006-04/rhf/index.php), (part-3 http://reefkeeping.com/issues/2006-05/rhf/index.php) >> I have only been doing this for about 8 months, and it seems everyone we talk to at the local fish stores gives us different advice, use this/you don't need that, etc. etc. <<Ah yes, understood...but it is no different here my friend. Opinions/differences of opinion still abound. You need to spend some time reading/educating yourself and then applying your own good judgment to make decisions>> Again, thanks for your time. Kelly Hood <<Read through the material I have indicated, and feel free to come back to me for further help/explanation. Regards, Eric Russell>>

Skimmer Ozone Question 10/2/07 Hi Crew, Thanks again for the great resource that is this website. Don't know what I'd do without it actually. <More reading? TV? Conversation, reflection... fooling with your tanks!?> Anyway, to the question at hand. I'll be running ozone on a new set-up I've been busy with for what seems like forever. I was thinking about connecting my two skimmers in series to each other so the outlet of the ozone skimmer runs straight into the 2nd skimmers inlet. I was hoping that this modification would allow more O3 to be blown off before it hits the carbon and then the tanks main body of water. Would this work? <Likely so... you could/might test... maybe pH, DO... see what sort of difference this makes> I was thinking that this set up would also increase contact time. What do you think? Would this be beneficial or would it be more advantageous sticking with a traditional set up where each skimmer has its own separate feed? Regards, Rafiq <Worth experimenting re... Not likely a big difference in any case here. Bob Fenner>

Sanders PS. Ozone Application 9/27/07 In your FAQs you mention the Sanders protein skimmer as a cheap skimmer to inject ozone. I can't find that available anywhere. Any links to where it can be purchased or effective cheap alternatives? <Don't believe too many etailers carry this anymore, probably costs more to ship from Germany than what they are worth. Try these etailers for inexpensive skimmers to do your job. www.premiumaquatics.com, www.drsfostersmith.com. James (Salty Dog)>

OZONE REACTOR usage with a 500 gallon fish-only-with-live-rock aquarium 9/27/07 Dear Sir: <Okay> I am in the process of setting up a 500 gallon fish-only-with-live-rock aquarium containing around 700# of live rock (rock receipt is expected in a few weeks after curing). <Mmm, do read re placement... Here: http://www.wetwebmedia.com/lrplacingfaq2.htm You may not want, need this amount of rock... depending on tank shape, density...> The tank also has a 120 gallon sump that will be setup to grow macroalgae in a mud bed. <Nice> The sump came with a skimmer, but the sump/mud manufacturer recommends only running it approx. 2 to 3 hours at night. <Heeee! Likely friend Leng Sy...> They state that this is due to the special mineral laden mud supplied, and the claims that excessive skimming will impact the mineral/nutrient carrying benefits of this "natural method" refugium system. <Yes... best to arrange the sump areas such that the mud portion has a minimum of flow over it... like five or so turns per hour... Run the skimmer on a punctuated basis or not... as you deem fit> I plan to quarantine and introduce Marine Angels, Large Tangs, Large Wrasses, a Ray, a few snowflake eels, and a grouper. <... Okay... can be trouble... do research re the compatibility, order of introduction of such...> I have purchased an electronic controller that has the capability to control ORP and I did buy a lab grade probe to go with the controller. I had planned to just monitor ORP, but after exhaustively reading your Ozone FAQs, I am exploring the attributes of actually running an Ozone generator and controlling ORP along with this setup. Your FAQs and answers convey several benefits. Alternatively, I do not plan to use a UV sterilizer (with all of the periodic bulb costs, etc.) but would rather use ozone. <Me too in this setting> I am trying to reconcile the recommendations of the sump manufacturer regarding limited Skimmer operations, with my desire to provide the benefits of ozone. Is there is a way to harmonize these options/recommendations? <A few... but a controller will "do" this limiting in either case> (I would presume that if the Skimmer was used as the ozone delivery device that its limited operation would preclude ozone effectiveness and not be worthwhile. Therefore, it appears that I need to use an alternative, dedicated delivery device. This way, I could run the ozone generator/system continuously and independently of the Skimmer, with ORP control via the electronic Controller.) <Mmm, yes> I have seen the term "Ozone Reactor" but, when Googled, I get limited information. Is there a device, different from a Skimmer, that could be used for effective ozone delivery but not negate the effects of the nutrients of the "natural method" refugium system. ? <Mmm, yes again... the term encompasses both skimmers of many sorts as well as purposeful (generally enclosed) reaction chambers...> If so, I would desire to purchase one. Any information regarding this option would be most appreciated, including configuration and hookup options and most importantly, where I could purchase one? Regards. John <I do hope to not be misunderstood here... but want to just skip ahead and suggest that... if this were my large FO first foray... I'd go ahead, run the skimmer continuously (sorry Leng) and use the ozone there, returning the ozonated water to the sump... Bob Fenner>

Ozone Injection...How To Configure? -- 09/27/07 What's the best way to hook up ozone to an ASM skimmer? <<Straight to the venturi tubing>> Right now I have a T into the venturi. With an air pump on I was getting a lot of residual ozone smell, and it was suggested to me to remove the pump. <<Mmm, yes...would need to see just how this ' T ' was configured, but I suspect you were blowing ozone back through the unit in to the atmosphere>> Would I be better off just injecting it right into the body of the skimmer? <<This is how mine is configured to my ER skimmer. The venturi will 'pull' the ozone in to the skimmer just fine...unless you are using a dryer that restricts the air flow greatly. In that case, you can hook an air pump 'in-line before the dryer' to boost flow. EricR>>

Re: Ozone Injection...How To Configure? -- 09/27/07 Duh wasn't thinking. The ASM isn't a venturi, it is a needle wheel. Does that change your answer? <<Ah, but the pump uses a venturi to draw air in to the needle-wheel so no change, my previous answer stands. EricR>>

Will GAC in Ozone reaction chamber effluent support bacteria? Mmm, maybe 12/16/06 Hi folks, <Robert> I understand from my readings that: 1. Effluent from an ozone reaction chamber is likely to have a very high RedOx reading of 600mV plus <Yes> 2. This effluent will contain a toxic level of dissolved ozone and ozone byproducts such as hypobromite <Mmm, can, yes> 3. Activated carbon in regular reef water quickly becomes colonized by bacteria <Very often the case... within a few days... populations climbing under various conditions...> 4. Activated carbon can remove the ozone and byproducts BUT 5. Activated carbon does not affect the RedOx of ozone chamber effluent <Mmm... actually... can to a degree> 6. Very high RedOx potential (much over 450mV) in water is toxic to life <Higher, but yes, there are practical limits> So, if I pass the effluent of my ozone reaction chamber into another chamber containing activated carbon, can I assume that no bacteria will colonize the activated carbon due to the high RedOx in that effluent water? <Highly likely that their metabolism, reproduction would be greatly attenuated... Might I ask... as you have given obvious thought to this "question"... How might one test for this hypothesis?> Many thanks in advance, Rob from Cape Town <Bob F in San Diego>

Re: Will GAC in Ozone reaction chamber effluent support bacteria? 12/18/06 Hi Bob, <Robert> Many thanks for your reply. <Welcome> In answer to your question: >>> <Highly likely that their metabolism, reproduction would be greatly attenuated... Might I ask... as you have given obvious thought to this "question"... How might one test for this hypothesis?> >>> I presume an answer would be to look for metabolic byproducts, probably carbon dioxide. <Perhaps something else... with a tracer or immunofluorescent properties> The flow rate through this chamber would be low, so there should be plenty of time to accumulate CO2 measurably. Two tests, one before and one after the GAC should show whether the carbon chamber is producing CO2. CO2 would drop the pH, so a pH test could possibly be used instead of a dissolved CO2 test. Although, now that I think about it, residual ozone reacting with the GAC would also produce a little CO2. <Yes, especially "when new"> I was hoping to use four reaction chambers in series, namely ozone, GAC, elemental sulphur, calcium carbonate. The ozone would produce nitrate from ammonia and nitrite and oxidize DOC to bacteria-edible smaller molecules. The GAC (I was hoping) would support sufficient bacteria to break down the oxidized DOC further and consume much of the remaining oxygen. The bacteria in the sulphur chamber would remove the nitrate, and I would need less sulphur than the recommended 1% of tank volume since much of the oxygen would already have been removed by the GAC chamber. Finally the calcium carbonate would dissolve to correct the pH and add some calcium. <Sounds like a very nice plan> None of this will work if the water flowing through the system has a poisonously high RedOx level. Do you have any suggestions as to how to fix it? <I think the measure you're talking about will actually work... the RedOx potential won't be so high...> Should I just split the chambers up? Ozone and GAC together and sulphur and calcium carbonate together? <Mmm... I'd keep these separated... for removal, inspection... ease of manipulation> I feel somewhat disappointed. They seemed to work together in such a complementary fashion until I thought about the RedOx problem. Thanks again for your help and apologies for the length of the mail, Rob <No worries re the length of mail... Important to make known what we want. Bob Fenner>

Re: Will GAC in Ozone reaction chamber effluent support bacteria? 12/20/06 Hi Bob, <Robert> Thanks so much for your help so far. It's invaluable to have someone with experience to talk with. <A pleasure to discourse> I've included a CAD image of the design. Would you mind having a look at it to see if there are any obvious flaws? I'm new to CAD so apologies for any amateurishness. <Ahh, a wonderful graphic!> Each canister is 140mm diameter by 600mm height. This is around 9 liters per canister. <Good size> My main tank volume is 1300 liters. This means that the canister size is somewhat less than the 1% of tank volume recommended by Langouet. I have a low starting nitrate level and other denitrifying mechanisms (plenum, live rock etc.), so I'm hoping this will be okay. <Yes, should be on these counts> The flow rate will be around 9 liters per hour. The recirculating ozone chamber will be about 4 liters in volume. This means that a given milliliter of water will be exposed to ozone for around half an hour. The ozone generator I have is rated at 300mg/h (not adjustable). I think this implies an ozone concentration of around 33ppm in the chamber. <Yes... initially... will be quickly degraded... changed into di and mono-atomic portions... the single oxygen used up... readily...> With the low flow rate through the device I'm happy to completely sterilize the water and break down pretty much all dissolved organics into bioavailable fragments. I'm going for a "9 liters per hour water change" sort of philosophy with this. <Yes> I'd very much appreciate any advice before I actually get into my workshop and start making the thing. <I like your diagram showing the true unions twixt the canisters... I would like to add a few union valves here as well... on at least the ends of the array> Best regards,
<And to you. Bob Fenner>

Ozone use, ETSS Skimmer 11/28/06 <Bob, I assume the TraylessQs folder is unreadable messages. If I'm incorrect in this understanding, do let me know. Original email address was . Message is as follows. -JustinN> <Thank you for this Justin> Dear Mr. Fenner, <Bob> I am new to your website and find it a fabulous forum for all kinds of professional advice and information. I do have a question that you have probably been asked 1000's of times. Please forgive my asking it again. It involves me (nervously) starting to use Ozone in my tank. I will be using a Microzone 300 Ozone Generator and a Milwaukee OPR Monitor/Controller to control it. I have a 135gal Reef Tank (LPS and SPS mostly) with 125 lbs of live sand and 125 lbs of live rock which houses 12 fish (5 Tangs, 2 Perc Clowns, Flame Angel, Coral Beauty, Lawnmower Blenny and some other ugly fish my wife bought). <Careful here...> After reading your excellent book (The Conscientious Marine Aquarist), and many of your responses to Ozone questions, I have one question I couldn't really find an answer for. I use an ETSS 800 Protein Skimmer that empties back into the bio-ball chamber of my wet/dry sump. I want to use Ozone in the Protein Skimmer and am concerned about the return water emptying back into the bio-ball chamber. <I see> Will the return water, now 'ozonized', from the skimmer kill off anything on the bio-balls, and then will it harm my tank if I do not run the return water through carbon? <Mmm, highly unlikely to be a problem here... given the action of the ETSS unit in mixing air/water... and the rapid use therefore of this miniscule amount of O3> In other words'¦ Please tell me a definite yes or no.. Do I need to run the return water through carbon or not? <Almost 100% no> I'm very nervous about this and don't want to harm my system in any way. Please give me your advice. I would really appreciate it. One other question if I may'¦ Should I set the controller to 300 or 350? <Try the lower setting, look for/measure incipient change in pH or other... and re-adjust upward with time. Bob Fenner> Bob Drews Ft. Lauderdale , FL P.S. Is it possible to call you, or have you call me for a consultation? <Mmm, don't "do" calls... Better for all that if an item can be put into words... that this be done, shared... But may be down near you for Xmas (Lauderdale Lakes, visiting mum-in-law)... and could meet then... Do you scuba dive? Been to Splashdown Divers in Boynton Beach? Bob Fenner>

Re: Ozone use, ETSS Skimmer 11/28/06 Hi Bob, Thanks so much for the quick response and for your expert advice (especially in calling my wife's fish "ugly" LOL). <Heeee! I did NOT. Only urged your caution in such labeling> OK.. I will run the Ozone w/o carbon and see how it goes. <Very likely will be fine> I have another question if I may. Do I have to worry about the hoses and other rubber / plastic components under the tank stand from deteriorating because of the ozone? <Mmm, no... a minor concern here> I can clearly smell ozone under there. And can that ozone I smell harm my wife, dog, and myself? <No...> I would love to meet you when you come down to Ft. Lauderdale, FL. I live right near Lauderdale Lakes. If you could let me know the dates you will be in town I will gladly arrange to meet you. And Yes, I do dive. I am a PADI Dive master/AI. Would you like to go diving? <Yes... I generally do when visiting there> I can take you down to the Keys for a day trip or something like that. Thanks Again, Bob Drews <Even better! Will try to keep your email on hand in anticipation of this adventure. BobF>

Re: Ozone Warning Signs 12/24/06 <Bob, am writing as I head out to put on the second coat of paint on the driveway... This close to the big day (Xmas and leaving) am writing to say thank you for your kind offer, but am not able to get about this trip with you. Hoping for the future... BobF> Bob F, Thanks for the email. I understand what you mean with loads to do myself. But thanks for the consideration. Let me ask you a question. I just started using ozone again a few days ago and I can't seem to get the ORP over the 300 mark. Do you think I should use an air dryer and small air pump to get better efficiency and more ozone into the ETSS 800 Pro Skimmer to help increase the ozone dosage? <Mmm, you could... the humidity is high here today for sure... But a reading in the 200's is really fine... One way to put this might be, what else might the money be spent on...?> Merry Christmas !! Bob Drews <And to you and yours Bob. BobF>

Ozone Help 10/14/06 Hi there, <Hello> I'm in the market for an ozone generator for my 180 gallon system. My question is, can I buy a small generator like the Red Sea Aquazone Ozonizer -which is rated for 100 gal, and not have to worry about buying a monitor? I understand that excess ozone can be dangerous. <Very dangerous 'to you and your reef> Could small amounts still be beneficial, and eliminate the worry of an overdose? <Definitely> Thanks so much for the advice. Your site has been helping me keep a happy healthy aquarium since day one. Colin D. <Colin -- Ozone can be a good thing as well as a bad thing. I personally don't use it due to the health risk to humans. I think that using smaller amounts can be beneficial, but I would still monitor levels in your tank. Cheers! -- Dr. J>

Ozone 8/15/05 Hello Wet Web Crew!!!! <Michael> I read everything I could find on Ozone on your site and Googling. It seems like sometimes a specific question has to be asked. Sorry to bother you if I could have found the answer and missed it. Ozone application, I realize most gurus recommend application of activated carbon for the effluent before it is returned to the display. I also find that most questions have been answered suggesting returning the effluent to the sump for further off-gassing. My point finally... I would like to pass the effluent through a dedicated activated charcoal media chamber ( i.e.. forces all water through the media) for excess ozone removal, then straight back to the display. Even though I have a 70 gallon sump, I want the skimmer effluent to be part of the display turnover as opposed to closed loop application to the sump only. Now I have read that ozone doesn't last long and converts to oxygen rather easily. <Yes... almost instantaneously for the vast majority of cases with aquarium units> I have read articles that have suggested the levels in spas and aquariums applied venturi method may last as little as one second before it is rendered harmless. I will be passing the effluent through a Pentair Mechanical Media device (37 inches tall!), should I go closed loop to the sump for further off-gassing? <I wouldn't> or do you believe that I will be fine going straight to the display from the skimmer through charcoal? <Yes> I hope I got that right. By the way thanks for everything that you guys are writing (tome wise) and doing WWM wise.... I have most everything Bob and Anthony have written. Write some more...... :0) MJ <Do, most every day. Cheers, Bob Fenner> Ozone inject ? 2/3/06 Is it possible to simply put an ozone feed air stone at the bottom of a tank overflow. Principle would be similar to counter current skimmer? <Yes, is possible. Some folks have a fear of livestock-ozone negative exposure... with most units/amounts of O3 this is not a valid concern. Bob Fenner>

Ozone Application - 04/27/06 I am having trouble finding reliable ozone advice. <<Let's see if I can help>> My setup is a 180g display heavily stocked. 100g sump, 20g fuge, 50g grow out tank, so 350g total. <<Ok>> 1. How many mg/hr should I get? I like to over-buy when possible for future upgrading, would 300mg/hr be enough? <<I believe so, yes. Differences between systems other than just "size" would ultimately determine need, but I have a very high quality (Ozotech) 250mg/hr ozone generator on my heavily stocked 500g system (375g display, 75g sump, 55g refugium) and I don't run it "wide open">> 2. How do I connect the output of the ozonizer to my ASM G6 skimmer? <<Most Ozonizers will come with instructions/adapters for such...is a simple matter in this case to hook the ozone output tubing to the air intake tubing on the skimmer pump>> 3. I will have an ORP controller, where does the probe go? <<Somewhere distal to the skimmer effluent. I have mine mounted through the top panel of my display tank>> This will turn the Ozonizers production on and off to keep ORP at a desired level? <<Won't "keep" it a set level per se, but will turn off the generator when/if the ozone reaches a certain set-point. REDOX levels will fluctuate throughout the day based on many factors (oxygen levels, lighting, presence of organic matter <feeding>, etc)>> So does it matter if the mg/hr is too high for now? <<The controller will keep you from "overdosing" your tank, yes...if set correctly>> 4. With 300mg/hr is carbon really needed? <<Some debate here I suppose, some folks feel the skimmers used by/available to hobbyists are not powerful enough to be of concern. I don't use carbon to filter the effluent from my skimmer, but when the generator is set to maximum production I do notice a reduction in micro fauna in my sump. It would be a simple matter to place a bag of carbon under the skimmer effluent if you have any concerns re residual ozone>> 5. If I buy a unit without a dryer, can it be added later? <<Yes>> Thanks for your help, Rory <<A pleasure. Regards EricR>>

Ozone and Ocean Clear Carbon Reef Tank, carbon... 8/13/06 We have a 250 gallon reef and are planning to use a small amount of ozone - 25-50mg through a reactor at a 300 gph flow rate. I was paranoid about any ozone getting in the tank (especially with bulkheads in the bottom of the tank), so I purchased a used Ocean Clear Carbon canister filter to pass the water through before returning to the tank. Now I'm not sure if it was the right thing to do (haven't installed yet). It holds 7 lbs of carbon. <Yeeikes! An unnecessary expense I assure you> Will a canister be okay to use in this case even though it is a reef tank (tank is a DSB Acro tank with zero nitrates)? <Would be fine, just not needed> If so, is 7 lbs of carbon okay or too much? <Depends on quality mostly... I would not start with this much material... perhaps a pound or two> How long can we go between carbon changes - I'm assuming if it is okay to use it would become a bio filter after a few weeks? <Mmm, yes... and progressively more so over time... I'd switch out a pound or so per month (best to use a pre-bagged product... like Chemipure, or get Dacron "purse string" bags and make your own...> If it is not okay to use, what is the difference between the canister carbon filters and carbon reactors? Thanks! Doug <Can be little or great difference in cost, capacity, absorbency... See WWM: http://www.wetwebmedia.com/carbonfaqs.htm and the linked files above. I myself would not worry re the ozone here... this amount will "be gone/disappear" in reaction almost immediately. Bob Fenner>

Big Tank, Water Quality/LR, Ozone, Curing LR 8/13/06 I am curing around 1500 lbs of rock in about 1200 gallons of water. <Mmm, a note for browsers... such large amounts of LR can be cured "in place" in large systems, but I encourage this elsewhere... much easier to manipulate, much less messy/stinky> There's about 40,000 gph of water movement. I've got two AquaC skimmers rated for up to 1000 gallons cranking overtime (with ozone on when the ORP drops below 390 and off at 400). <Rather a "tight" setting... I'd move the lower value down to the 350 or so range> I scrubbed it all pretty good before I put it in, but have only done minor incidental water changes (leaky plumbing and VERY aggressive skimming). Its been almost two weeks since I first introduced the rock. Nitrites are around 4.0 ppm, <Too high> nitrates are around 20 ppm <Way too high... these values spell the doom for too much of the "live" portion of your rock. Should be kept down...> (both have seen a huge decline in the past few days. The pH has been staying high - ranging from 8.1 - 8.6. <This is the ozone, not biomineral effect> My real query is about my ORP. Until this tank I've never had the equipment to monitor or regulate my ORP before. Its currently at 419 and still on the rise from what I can tell. <... too high...> Honestly I don't think I fully understand the concept from reading the article on the site, but from various Q and A's on the site I gather that this is not that big of a deal as long as its not ozone that's raising it that high (which it's not in this case - at least not from the Ozonizers). <... Really? What is "it" from? Have you tried turning off the ozonation?> My water is still quite yellow however, despite running carbon and PolyFilters and ozone off and on. <Massive die-off effect> Due to the location of the tank it would ideal if we could expedite the un-yellowing of the tank. Thanks for your help, Scott Sent via Blackberry from T-Mobile ²[% <Neat... Well... to start with, though it may seem expensive, I would make a very large water change here... perhaps half... Next, I would carefully (like two separate test kits) measure alkalinity/acidity, and look into the means (there are a few... and this can be confusing for sure) of bolstering the same... with a source of carbonates and bicarbonates. I would look into your calcium, magnesium concentrations as well... these are likely out of whack, and relying on the water changes alone will too-likely drive you bonkers as well as to the poor house... When you have occasion/time, do take a read over WWM re the concepts of alkalinity, this and pH... the use of supplements for same. Bob Fenner> Applying Ozone...Venturi or Not? - 10/01/06 Dear Crew, <<Hello Rafiq>> Thanks for a great service, I would probably be poorer and animal heaven more crowded without it! <<Indeed my friend...is our hope/purpose to enlighten/educate...and thusly prevent needless misery/save lives...>> I recently purchased a 500mg/hr ozonizer and ORP controller, <<Big unit>> I was planning to add the ozone to a PVC, DIY recirculating, venturi type skimmer by drilling a small hole at the top body of the skimmer and dropping in an airstone or limewood (is that what those 'woodstones' are called?) into the skimmer reaction chamber. <<Limewood supposedly makes the "best" wooden airstones...Basswood does a good job as well in my opinion, and is more readily available (in my experience) if you want to make your own stones>> Is this a correct/reliable method of applying ozone to my aquarium? <<Yes...I prefer to apply ozone through a skimmer. But you would do well to merely attach the ozonizer to the venturi and let it "draw" the ozone from the unit>> I have considered attaching the ozonizer directly to the venturi but I get the idea that the venturi draws air at a rate far higher than the ozonizer can generate. Is this a valid concern? <<Not in my opinion. The venturi will draw the available ozone as it is generated...how fast it generates opposed to how much air the venturi draws need not be a concern>> Will both methods work? <<Probably>> Is one better than the other? <<I prefer the "venturi" method>> Kind Regards, Rafiq van Greuning JHB, ZA <<Cheers my friend. Eric Russell...SC, USA>>

Super Reef Devil + Coralife ozonizer Hello, <Cheers... Anthony Calfo in your service, telling everyone that Bob is in Australia when he really has taken a "judicial detour" after getting picked up for skinny dipping in a local university fountain. He says he was looking for wildlife... and judging by the reported sorority brand ("Property of...") on an undisclosed location of his person... I'd say he found it> I own a Super Reef Devil (SRD) protein skimmer. It has taken me 3 frustrating weeks, but it is now running *very* well. (I had to elevate it in the sump (1.75 inches) and add 2 additional bio-balls (for a total of 10)). It took 3 long weeks, but the results have been well worth the wait. <necessity... the mother of invention. Kudos to you> **NOTE** Word to the wise. The instructions that come with this skimmer are GROSSLY inadequate. Set up is not the issue. Tuning is the issue. <as it is with most skimmers> Prior to hitting the 'magic combo' (elevate 1.75 inches in sump plus add 2 bio balls) I thought I wasted my money. Now I think the SRD is wonderful (it pulls burnt coffee colored skimmate from the tank to the tune of one full collection cup per day. Bio-load is light to boot, as the tank is only 3.5 weeks old. I had one day last week when it pulled 3 full collection cups of skimmate from the tank (I was experiencing a severe outbreak of diatom algae at the time)). ** END NOTE** <Excellent!!! Thank you for passing this along. ATTENTION: All Daily Q&A Readers... this is exactly how a skimmer should work. Yes... in a young, low stocked system you should still be able to pull out a cup of dark skimmate daily. So for tanks that are more established with fishes and haven't produced skimmate consistently... do not let yourself think that there is not much to skim. It will catch up eventually beginning with nuisance algae (thanks for the info and diversion Mark)> After much reading (including your very informative website) I am debating purchasing a Coralife Model 50 electronic ozonizer (or maybe the Model 100). I've never used an ozonizer before. Therefore, I have the following newbie questions: 1) In general, how is an ozonizer hooked up to a protein skimmer? <in-line with the venturi or other air supply> 2) Is it possible to hook up an ozonizer to the SRD? To any skimmer? <yes...to any skimmer indeed. Even if that means adding a small airline> 3) Is there someplace (on your site or someplace else) where I can review some sort of set up and/or planning guide? <I haven't exhausted the archives but do a keyword search on this site only (tag the bullet on the Google engine) for ozone... we have answered some recent replies that may be helpful> If it is possible, and not back-breakingly difficult, I would like to run ozone to improve the already pretty darn good skimming performance of my SRD (okay, so I'm greedy). <agreed... it will improve skimming through saponification, raise RedOx and O2 levels, is antiseptic and improves water clarity noticeably which will help with light penetration for corals> If it helps, my SRD in is my sump (a 20 gallon long tank (30" x 12" x 12", I believe) located directly under my main 75 gallon tank. Between the sump and the Eheim Pro II 2028, there is not a lot of room left under the tank -- some, but not much. <the electronic ozonizer is very small and does not require an air dryer like corona discharge units> If you need any additional info, please let me know. I want to make sure that I can actually use this model ozonizer (or another) *before* I spend my money. I know my wife would appreciate it :-() <make sure you pass all effluent water over carbon and also coordinate the application of ozone with a RedOx meter or controller (better yet)> Thanks in advance. Sincerely, Mark Schwartz <very welcome, my friend. Anthony Calfo>

Super Reef Devil + Coralife Ozonizer II Anthony, I contacted A.E. Technology (manufacturer of the SRD). They told me that using ozone on that skimmer was not an option (they actually used the word 'dangerous', but did not elaborate, and I did not press the issue). <wow! There are only two explanation for this: 1) they are mistaken and do not truly understand and appreciate the merits of ozonation and 2) they have used a really cheap grade of "plastic/acrylic" that is destabilized by ozone. Good quality skimmer plastics and PVC can handle ozone with no problem. Two of the biggest European skimmer manufacturers (Tunze and Sanders) give specific instructions on how to apply ozone through their skimmers. Ozone misapplied is indeed dangerous just like iodine supplements and a lack of water changes... but I would not have insulted your intelligence by saying that they were "dangerous" without at least elaborating> They also felt that I would not see much, if any, improvement in performance (a little surprising to me, but they know more about skimmers than I do). <no my friend...trust your instincts. They give you an admonition and don't explain it...hmmmmm? As I stated before... ozone and UV are really only necessary for commercial applications (new fish/coral in and out frequently). Few home aquariums truly need them (especially if you are QTing properly) although some do benefit by it in special circumstances (high bioloads, coral fragging/farming, overfeeding fish/coral for growth, etc.> Thank you for your assistance. I do appreciate it. Sincerely, Mark Schwartz <best regards Mark. Anthony>

Re: Ozone Question Anthony, Thanks for your quick response to my ozone question. <quite welcome my friend> I have the Coralife ORP controller working OK. and just picked up a Clearwater Tech model MZ-250 ozonizer from a friend. I have one last question though. My TUNZE 3115 skimmer sits inside my tank. How do I carbon aid the output for residual ozone? Again may Thanks for all your help. John <the in tank design of Tunze is actually quite brilliant when applied to an aquarium with an overflow... this allows the skimmer to operate at a very consistent level (and subsequent head) of water whereas a sump model skimmer that is not placed in a dedicated overflow box must suffer sump fluctuations which significantly impact performance. Unfortunately in this case... you really cannot release ozonated water into the aquarium through this skimmer. Once possible solution is to have a small skimmer box made just slightly bigger than the skimmer and drilled with an appropriately sized overflow hole. This skimmer box can be placed above or slightly out of the tank water (fed by a dedicated pump or the sump return) or perhaps better yet, placed downstream of the overflow (between the overflow drains and the sump inline) catching raw tank water. Either way, the overflow of this skimmer box can simply pour into a bag of carbon before continuing on. Ozone is a great benefit when used properly, but if abused can harm aquarium inhabitants and even you if enough gets into the air without carbon filtration. I personally like using it... many merits to its application (Disease control, increased RedOx and O2, improved water clarity, etc). Best regards, Anthony>

Berlin Skimmers and Adding an Ozone Unit I am thinking about adding a ozone unit to my 75 gallon tank. It has fish live rock and some brain corals, maze corals. I have a Berlin classic skimmer inside a 20 gallon sump below the main tank. It has been upgraded to the turbo model. I read on the box it is not ozone compatible the upgrade I am assuming. The skimmer itself says its is ozone compatible. I am looking at buying the Red Sea deluxe with controller and probe. Not sure what size to get though. 100 or 200 model. Are they hard to hook up? Do you know if I should go back to the original venturi in the skimmer and run a larger power head than they send in the turbo upgrade? The turbo model does not seem to collect that much waste, or I may not have it set just right. Which is probably the case. I have the water flow on the turbo power head all the way up with air control valve about half closed. I do have the water coming down to the sump going through a 100 micron bag filter. I do not know if this will cut down on some of the work the skimmer has to do. I friend said to use a power head with venturi action and a needle impellor. I cannot find one of these powerheads. Any Ideas? <Honestly? You can spend a fortune trying to make your Berlin (Edsel) a Corvette, change the engine, ignition, etc. It will still be an Edsel. Consider one of the better skimmers designed for ozone (if you really need it, which is doubtful). We all like Aqua-C and Euro-Reef skimmers at WWM. Perhaps take a look at the new Euro-reef ES Series skimmer for in-sump use. Some of the Euro-reefs and Aqua-C's come with ozone capability. Craig>

Ozone Stable Plastic - 2/14/03 can i use a AMiracle counter current skimmer as a ozone reactor? thanks <the correct answer is a serious matter. Do consult the manufacturer to verify if their acrylic is ozone stable. Anthony>

Ozone With An Aqua C Urchin Skimmer? Hi guys! <Hi there! Scott F with you> Just wanted to know if you have any experience about applying ozone to an Urchin Pro skimmer, maybe adding an airline with an airstone, or something similar. <Hmm...Not personally, but I'd recommend contacting either the manufacturer, or perhaps put a post out on the wetwebmedia.com chat forum to see if anyone has tried this.> I am planning to upgrade my non-skimmer (SeaClone) to an Urchin, but I use ozone and wanted to see if anyone has had any experience with this skimmer. I wish I could get a bigger skimmer, but my sump is very small and the Urchin seems to fit nicely. <It is really an excellent skimmer, and will do a great job for you!> Also, just as a quick fact, I sent AquaC a couple of e-mails to them, and promptly got a response from the president of the company. Now that is what I call costumer service!! <Aqua C's owner, Jason Kim, is one of the nicest guys in the industry, and, being a hobbyist himself, is always helpful and enthusiastic. I'd bet that he could give you some tips on the use of ozone with this skimmer! Try contacting him again!> Thanks, Harold Chamberlain Costa Rica <Sorry I couldn't be of more assistance to you...Do contact Jason again- I'm sure he'll have some ideas on this! regards, Scott F>

- Ozonizer Set Up - Hello, <And hello to you, JasonC here...> Once again, I'm at your mercy and begging for help! I purchased an Aquazone Plus 200 Ozonizer with probe and Sanders Air Dryer on eBay. Just as I suspected, I can't figure out how to use them. I am using a Remora Protein Skimmer but it has been modified to sit in sump and powered by a Maxi-Jet 1200 power head. Where and how should I pump the ozone in? <I guess, ideally it should go into the skimmer via a venturi on the pump.> Should I use the air dryer? <I would.> Could you just come over and hook it up for me? <Sorry, no...> I have read over the FAQ's on Ozonizers, but I need specific directions! <Then you should contact Red Sea, the people who make it.> I'm new to the marine aquarium hobby, mechanically challenged, and blonde! <No worries, it's not very complex, but some manufacturer's recommendations would really help.> Seriously, if you can help me out, I would greatly appreciate it. Lynn <Cheers, J -- >

- Ozone HELP - <Greetings, JasonC here...> I just hooked up a Aquazone 100 with controller and probe on Saturday. I have it going into a Aqua- C EV-120. It made a incredible difference in clarity. I have not received my residual ozone test kit yet. I had it set a 30 ml and ORP set at 300. The ORP was 240 when I first hooked it up Saturday according to the pin point probe. I have read on your site to have the exit water out of the skimmer to go over carbon. <Not really so important - the AquaC EV series of skimmers is very efficient, and with all likelihood 99.999% of the O3 is used up by the time it leaves the skimmer.> I could not figure out a good way to do this, so I put carbon in my sump. I got like 5 bags of Chemi-Pure right around the exit port of the skimmer. I have not contacted Aqua-C as of yet to see if they make something that can screw into the exit port of skimmer and add carbon to. Right now I have a plastic cup with holes drilled in it and a bag of carbon in it, plus 4bags of carbon. <Running carbon every so often is a good thing - running this much constantly is a drain on the wallet. Again, I wouldn't worry so much about excess Ozone.> Tonight when feeding the fish, I opened the canopy and could smell ozone. <Did you check your ORP reading at the time?> I shut it off for now. <I think you're safe - 30ml per hour is not a lot of Ozone.> I thought I had enough carbon in it. <The smell could have been from another source...> Also I noticed the skim was lighter which you said in one of your articles. Any ideas? <Don't worry so much about it.> My colt coral does not look good today, kinda sloughing. Is this due to ozone getting to the tank? <Probably not.> I thought I had enough carbon in the sump. I also have a Aqua-C waste container that has a place for carbon on the top of it and also has carbon in it. <There seems to be a lot of urban myth about Ozone generators going awry and causing havoc - I think these are mostly hearsay and where problems were caused, it was due to oversizing of the generators, and/or poor monitoring on the aquarist's part. Again, at 30ml/hr you're going to find it hard to get into trouble. Cheers, J -- >

Re: ozone Hello Bob and cohorts, I recently contacted Euroreef regarding the ozone compatibility of their skimmers and received the following advice... "We do not recommend using ozone in protein skimmers as it greatly reduces the efficiency of the skimmer and produces more nitrate in the system." I have heard some praise from you guys regarding the stuff, so I'll assume that it's good in some situations, bad in others. <Actually, am surprised by the second statement. Would you please send their (Jeff or Bob Macare's) response to you en toto?> Here's my rundown... 55 gal. w/ 20 gal sump., 15 gal refugium w/ Chaetomorpha, & 5 gal DSB 130 lbs. rock (split between main tank & refugium) 260 W of PC light, Euroreef CS6-2 skimmer EHEIM canister for carbon & PolyFilter B-Ionic is only additive NH3, NO3, NO2, PO4 - zero pH - 8.3 kH - 11 Ca - 460 sp.grav - 1.025 temp - 79 F O2 - 4 to 5 mg/l lots of LPS, soft corals, 1 squamosa, plenty of fish & critters I am concerned that this dissolved oxygen level is a bit low and ozone might help. <Should, yes> I understand saturation at my conditions is around 6.6 mg/l. <About this, yes> What are your thoughts as to me getting an ozone generator for my system? What would be the benefits / drawbacks? Is Euroreef on to something? I appreciate your advice. <This is a worthwhile addition, adjunct to your systems filtration. Would add one myself, and likely run through the skimmer... a small unit of a few tens of milligrams per hour of 03 production... Please see WetWebMedia.com under "ozone" re use. Bob Fenner> -Mario

Re: ozone Sure, here is the complete message (from Jeff Macare, 3/17/03)... --The skimmer is ozone safe. You can attach it to the silicone suction to the venturi. We do not recommend using ozone in protein skimmers as it greatly reduces the efficiency of the skimmer and produces more nitrate in the system.-- <... perhaps our experiences just vary... I'm of the opinion that "efficiency" is improved (if overall water quality is the measurable, desired result... and nitrates are reduced overall.> Pretty short and sweet. My original question was whether or not I should hook the air intake from the skimmer directly to the ozone generator. Thanks again for all of the shared knowledge, -Mario <Thank you, Bob Fenner>

Next Stop...The "O" Zone (Ozone Use) Please help. <Will try!> Its been 10 years since I kept reef tanks and I'm now confused. <It's been longer for me, and I'm STILL confused! Don't stress over it! :) > Back in the day I used to use a counter current skimmer and air stone with ozone injection. Now I am starting a new reef tank and I purchased a Turboflotor 1000 skimmer. The only problem is you cannot inject ozone into this skimmer. What I came up with, and this is where I need your advice, is an ozone reactor. Basically it is a 3" dia clear pvc pipe 30" long filled with BioBale. Water is pumped over the media and air and ozone is pumped in via a tetra Luft pump. The exhaust tube starts 1" off the bottom and the water is forced out by the air pressure. The water exits and passes through another piece of pvc filled with carbon to eliminate any residual ozone. Does this sound proper or could I just connect the output of my reactor directly into the input of my Turboflotor (without a carbon filter in line) or would the residual ozone in the water still corrode the plastic impeller assembly? <I like the idea of the "reactor", myself. I've seen similar devices in use before...I'd give it a go for awhile and see what kind of results you could get. I think that you will see less potential damage if the ozone is injected in this manner, although there are no guarantees either way...> Please help me I cannot find any information on this anywhere. <You might want to check out the DIY site ozreef.org and see if they have anything similar to what you're contemplating> Thanks, Mark <Glad to be here for you, Mark! Good luck, and keep us informed! Regards, Scott F>

Proper Ozone Addition... This is how I plan to connect Coralife ozonizer to my 90 gallon reef tank. The dosage will be 3mg/10gallons (max dosage for the ozonizer I have). It will be connected to the venturi port of my BakPak2 skimmer. I was told that the usual dosage is around 5mg/10 gallons, but that is all I have right now, so I hope 3mg/10 gallons will still be somewhat sufficient. <If applied properly, it may supply some benefit...> I was also told that since I connect the ozonizer to venturi of skimmer, I really should not worry about passing water through carbon, because one will react by the time water goes to the main tank. <Umm...I still like the idea of filtering some of the effluent water through carbon to remove possible residual ozone...Still a possibility, and better safe than sorry...> The main question I ponder is can I do without ORP controller for a few months? <Personally, I would not use ozone without an ORP controller...Haphazard application of ozone is potentially problematic...Maybe a low dose (mg/gal) is not too bad, but it's the practice of adding ozone without precision and control that would bother me...Don't get into the habit of using ozone, additives, or anything designed to manipulate tank environmental parameters unless you test or otherwise can measure precisely the dosage of what your adding! You know what I mean? Just good practice, IMO> Especially since the dosage is way less than the recommended average. So the questions that remain are: -Should I run the ozonizer all the time? <As above...I like control, baby!> -What are some overdose symptoms in fish and inverts that I should keep an eye on? <Difficulty in breathing, "burned" finnage...the signs will be obvious...> -Will 3mg/10 gallons still be beneficial? <If applied properly, it could provide some benefit...> -Is it possible for the ORP to be too high? <In theory...> -And finally will ozone take out any essential trace elements, such as iodine, calcium, strontium, magnesium etc. that I should increase supplementation of? <I would measure these parameters regularly if you are concerned about their depletion...Personally, I have always maintained that, in most situations, it's better to utilize regular, frequent water changes with a high-quality salt mix as your "supplement"...> Thanks, Luke <My pleasure, Luke! As author John Tullock always asserts- "Test, then tweak!"...Good advice, IMO! Good luck! Regards, Scott F.>

Ozone and its affect on plankton Greetings. <Hello there> I would like to know the affects of ozone on the planktonic stages of the reef critters in our tanks, pods, Stomatella, bristle worms.. etc. Does the Ozone really kill them like a UV would? <Don't have specifics, but beyond a RedOx reading of 400 or so I do believe O3 would become more and more toxic to larval forms of invertebrates, fishes> Do they become oxidized by the O3? Cell structure get weakened and they die? Will the use of Ozone wipe out a tank of plankton? Any info you can help or link me to would be appreciated. Thomas <Like "too much of any good thing", too much ozone would be harmful. However, its utilization as an adjunct to improved water quality would be beneficial... let's say to a RedOx reading of 300 or so. Bob Fenner>

- Ozone Questions - hey guys- I have a few questions about ozone. Pretty much all I know about it is that you have deemed it beneficial. After sorting through your articles and FAQ's, I am still a bit confused. More specifically, how would I hook this up to my protein skimmer (AquaC ev-180 w/out ozone modifications offered by aqua-c), maybe through a venturi on my intake line, or is it even possible? <Jason Kim will send you the fitting, and you can just drill a hole on the top of the skimmer body for the fitting - I would not put a venturi on the intake. Do contact Jason at info@proteinskimmer.com> I noticed this unit as an all inclusive kit by red sea including 100/mg/hr ozonizer/controller, probe w/ air-dryer 250, and was wondering if this is really all the equipment i need (i.e. no other controllers or monitors, air pump etc..), sufficient for my 80 gallon reef and an all around decent set of equipment? <Should do just fine - won't need anything additional, except perhaps for some ozone-resistant tubing.> And about ozone, what specifically are the benefits, dangers, optimum levels, and how they are obtained? <Please read here: http://www.wetwebmedia.com/marphysf.htm > Thanks for all the help you've provided me and other aquarists around the world, keep up the good work and am anxiously waiting for the next volume to be released, sincerely Justin <Cheers, J -- >

Ozone - To Carbon Filter or Not? I have read on your website that ozone for aquariums produce such little amount of ozone that there should be no concern about residual ozone reaching the tank and its inhabitants. <In the vast majority of cases this is so> I have a 40 gallon reef tank and a Red Sea Ozonizer (model 50) I have a small trickle filter (60 gallon) and an extremely small sump. My protein skimmer is small too. Only runs off a Rio 600 venturi (Pro Clear Aquatics 75 gal brand) Anyway, I am currently using carbon but don't want to if I don't have to just because the myth says so. My reasoning behind not wanting to carbon filter is that since my sump is so small (probably 4 gallons) the skimmer produces so many bubbles and pumps them into the tank. Prior to hooking up the ozonizer I simply pumped the discharge from the skimmer through a vent hole in the acrylic and it would pour over the bio balls and sponge filter in the bottom of the sump. This filtered out all the bubbles. I can't do this if I have to carbon filter unless I just laid a carbon bag over the bio balls and had the discharge spill onto the carbon bag??? <A possibility> Or not use carbon at all? Will residual ozone in discharge kill beneficial bacteria on the bio balls? <Doubtful... perhaps a small experiment... even just measuring pH of the effluent with the ozonizer on and off will settle your mind> The model 50 ozonizer was the smallest they make. Is this overkill for my 40 gallon breeder tank? Also, Only have 3 fish. Everything else is inverts and corals. Can I have the ozone set on 30% now which converts to about 12mg per hour. Is this too much? <Not too much> My ORP reads 162 and I am not seeing it go up after a few days. <This is low... I would increase the setting> I am shocked. Any thoughts? The ORP probe has a black cap on the end. It had a sticker that said to remove sticker to expose very small hole in side. Should I remove this cap? I don't recall ever seeing a meter with a cap on the end. Thought they were open? Thanks, Rob <Me too. Try removing it. Bob Fenner>

Follow Up: pH Test & Residual Effluent Ozone Bob, <Rob> Thanks for your response. I did test the effluent while the ozonizer was running as you stated and it is at 8.2. Can you explain how this determines that there is little or no residual ozone in the effluent? <Yes, as I suspected... it's all being "used up" very quickly...> I did find out from Red Sea that the cap should be removed. <Yes> Once I did this it gave me a good reading. I notice an amazing difference in how dirty my sponge filters get as well as how much algae grows on the glass and pre-filter. Don't know how I ever lived without it. Can ozone hurt live plankton? <Only if present in high concentration... very unlikely with hobbyist units> Recently purchased some DT's. Thanks again, Rob <You're welcome. Bob Fenner>

Follow Up: Ozone burning fish fins? Bob, Me again. Less than 24hrs after discontinuing the carbon I noticed a noticed an area about 1" long on the upper fin of my blue tang. Ever heard of ozone actually burning the surface of fish? <Yes... but not from the small corona discharge units sold for hobbyists> Guess it could be something bacterial and I am going to treat him in my hospital tank but thought it was odd that it appeared so quickly. Normally you can see a bacterial infection spread over time. What do you think? Thanks, Rob <Bacterial infections per se are rare in marine systems... almost always the real/net cause/s are environmental... with bacteria simply "cleaning up", decomposing specimens as it were. Check aspects of your water quality, quick. Bob Fenner>

Ozone Tubing Question for Red Sea Aquazone Ozone Unit and Euroreef CS6-2+ I just got the Red Sea Aquazone 100 mg/hr unit, and some ozone resistant tubing (1/4" ID?). However the tubing for my Euroreef CS6-2+ is much wider than this. Any thoughts/suggestions/tips on how I can resolve this? <Yep... look into a "reducer/adaptor", at Lowe's, Home Depot or such of "all plastic" or nylon construction... a big hint: bring the two sizes of tubing with you and fit over the barbs while they're still in the packages while there... and know that you'll likely have to replace the Euroreef tubing over time... with the effects of the ozone shrinking and making it more brittle. Bob Fenner> Thanks in advance for your assistance. Lonnie

Looking for specific ozone suggestions Hi, You have the best resource for marine info on the web. Thanks! I'd have to quit my job to read all of it ;-). <Mmm, maybe that's what happened to me in a sense> I have a 75g tank with a (Pro Clear) wet/dry and skimmer. I read up on ozone and decided that it was a good idea for me. I bought a generator/controller and thought I'd just hook it up to the skimmer. Unfortunately, I think it will be hard to maintain a level of water as the ozone turns on or off. It also seems that the suction from the venturi isn't enough to take the ozone, but that adding a pump will be too much (both causing overflow of the skimmer). Finally, the skimmer output currently goes back into the wet/dry to break up bubbles. Not sure if I should have it just go back into the (small) sump and rig up something to have it pass through carbon or something else. Adding to the confusion are the skimmer manufacturers who barely acknowledge ozone or out and out say they don't recommend using it with their skimmer. <Did "they" state why?> I'm open to all options including buying a new skimmer, setting up a second sump to adequately aerate and then filter the skimmer output, etc. In all of the FAQ, etc., I couldn't find any specific descriptions of how people have set up ozone (which skimmer, how is it plumbed, etc.). Also, while a reactor seems like a good alternative, I could only find one very expensive one online. Even with that, I'm not sure whether I should run this as a loop with an inline carbon filter from my sump with a separate pump. <If it were my set-up, gear, I would rig a (plastic) "tee" of good diameter (the size of the current venturi intake, and run both "other" inputs of the tee up higher than the skimmer, the "teed" side to the ozonizer (even if the tubing to it has to be reduced)... allowing the ozone to be "sucked in" when produced w/o resistance in the line... and not worry re the discharge of all into the sump.> I appreciate any specific suggestions. I'm anxious to get it hooked up. Thanks John <I hope this makes sense. Bob Fenner> Continuously injecting ozone Thanks for the previous responses. I have a question now about injecting ozone into my skimmer. I have a fairly large Beckett skimmer (40"), that has a lot of swirling/agitation/etc, so the ozone should all be worked off. <Not necessarily.> Right now its connected to an ORP controller for 350mV. There is carbon in a chamber post skimmer, so that helps as well. <These two do more than help, they work very hard to ensure that no residual ozone makes its way into your tank.> I'd like to continuously inject ozone into the skimmer chamber, rather than off/on which it is doing now. Even if the ORP is at 350 right now, is it feasible/safe to constantly inject a low amount of ozone into the skimmer (like 60-75mg)? <No> Will this raise the ORP too high? <Yes, and then burn/melt/oxidize your fish.> How can you consistently shoot ozone into a system when the ORP is already high? <Not a good idea.> Is my water quality/ORP staying high which is a good thing? <Yes> and injecting more just isn't worth it? <Isn't worth the risk.> Thanks, Jim <You are welcome. -Steven Pro>

Ozonizer attachment Hi crew, <Frank> I have just got hold of an ozonizer that I had intended to use in conjunction with a Red Sea Prizm skimmer and its own dedicated air pump, however it appears that I cannot attach it to anything to introduce it to the water. I am thinking about using a tee piece to attach it and also let the pump in the skimmer draw air as well. Do you think this solution will work as when I attach the air pump directly to the air injector the pump stops drawing water from the tank. Is there any other solution to introduce the ozonizer to the water? <With this unit it should be able to be adjusted such that you can hook up the ozonizer discharge to the air-venturi... and adjust the valving to have this material "sucked in". Do you have a fellow marine aquarist friend there that can come over and help you in person? The folks at Red Sea should be able to describe this better. Bob Fenner> Thanks in advance for any help you can give. Frank from Glasgow

- Ozone Generator Placement - Is it safeand effective to install an ozone generator, such as the Red Sea line with ORP monitoring, in the sump of the wet/dry filter just before the protein skimmer?<Hmm... you'd at the very least need an air pump in front of the ozone generator to force the ozone into the water. One of the most compelling reasons to use the skimmer as the mode of import is their need for air induction, which makes it a common sense location for ozone input.> Will a significant amount of ozone escape into the ambient air? <Provided the model you choose is not oversized, the majority of the ozone will react with compounds in the tank. Any remaining ozone that escapes into the air will likewise react very quickly. Still it's wise to implement precautions - have activated carbon in its flow path, etc. Would suggest you think about using your skimmer to process the import of ozone.> Will that amount of ozone damage the biological filter, which is upstream but immediately adjacent? <Shouldn't.> Richard R. <Cheers, J -- >

Question about Ozone use Hi Bob, it's great to meet you, I love your book. My name's Austin, I'm a junior in high-school, I've had a 125 reef for 3 years and I'm upgrading to a 180g reef this weekend, thought I would ask your opinion on something! <Okay> I've ordered the Red-Sea 100mg ozone generator, some ozone safe tubing, an air dryer, and a controller with probe. I'm planning on injecting it into a EuroReef CS8-4 that I have. I was wondering; 1) Do I need an air pump at the air input to the ozone generator? Can it be too big, or will the ozone generator slow the air input down to what it needs? What brand/type will work best? <Likely you will not need such a pump... the intake vacuum from the skimmer will suffice> 2) As far as human safety, the skimmer collection cup has several small holes in the perimeter, would draping a bag of carbon over the collection cup keep the effluent air ozone free? <The small amount of ozone will not be detectable, dangerous... I would not be concerned here... All 03 will very likely be "consumed" in the skimmer itself> 3) As far as putting a "T" in with one end coming from ozonizer, one drawing in normal air, and one combing both and leading to the skimmer pump input, can a regular PVC "T" from Home Depot be used? <Mmm, it can... but do look at their smaller plastic parts area... including all-plastic ball valves... you'll want one of these as well> Isn't ozone safe tubing smaller than airline tubing, how do you adapt it to fit the "T" and to fit the skimmer pump input (Sedra 5000)? <Most is adaptable to 3/16" ID use... there are other diameters available... the real up/downside of using other, less-resistant tubing is simply more frequent (like annually) replacement/renewal> What's the best way to do this (I'm all for using a different method of getting the ozone into the skimmer if there's a better way :-)? <Just having the ozone aspirated by the pump/s of the skimmer> 4) Any idea whether Euro-Reef skimmers are ozone safe? <They are "sufficiently" ozone safe> Should I get some silicon or Buna o-rings to replace the black ones? Are these found at Home Depot? <I would not be (overly) concerned here... though you are smart to ask. I would query Jeff (or his dad, Bob) Macare at EuroReef itself re these issues. Their URL somewhere here: http://www.wetwebmedia.com/euroreefskimmers.htm> 5) For effluent skimmer water, the EuroReef skimmers output is just a tube that sticks straight up, can I put a "U" onto this so the water points downward and I can have that water go into a carbon bag? Better way to do this? <Again, I would likely dispense with this use... you can/could add the discharge "U"... but I would not> THANKS a LOT for your time!!! Austin <A pleasure to share. Bob Fenner>

Re: Question about Ozone use (and Carbon) Thanks Crew, just one more question, I couldn't find a really good answer on WWM. Is O3 really a reactive enough molecule that the third charged O will really jump off at the first chance it gets? <Well put... ozone, tri-atomic oxygen is quite unstable... does easily "fall apart" to monatomic (very reactive oxygen) and the far more stable diatomic form> Therefore is carbon on the effluent air and water really not necessary? <Mmm, well... carbon can be of use in its absorption... but practically speaking, the puny amounts made by aquarium gear generation... are so small, usually so transient (used up) that there is very infrequently any real value in such chemical filtration> If the effluent water has to flow from one end of a 65g sump to the other with 1200gph through the sump, is it likely that the ozone will disperse before it reaches the display tank? <Yes... not so much disperse (though this will happen) but engage in RedOx reactions> And with the airline tubing and o-rings would it work well to just replace them every year instead of trying to use different size Ozone safe tubing? Thanks a lot <Well put as well. Yes. Bob Fenner>

Heteractis magnifica 5/24/05--Part 2 + Ozone Thanks for the info, does not seem to be growing and maybe a small amount of shrinkage so perhaps I should increase the feeding. <Sounds reasonable.> On a different topic, I emailed awhile back on ozone use and have not heard back. <Sorry about that... with the large volume of mail that we get, we occasionally lose one!> On your site you refer to hobbyist ozone generators?? Not sure what they are, also from reading through your site it is seems to be the general opinion to run ozone 24/7. What is best way? through skimmer or ozone reactor? the unit I am getting will do 100mg and hour. Is this safe to run 24/7 with out an ORP controller? <Ozone is used in many industries. Normal oxygen molecules are O2, ozone is O3. Forcing the extra oxygen on makes ozone a very reactive oxidizer. Small units are made specifically for aquarium use. In appropriate doses, ozone helps clarify the water by oxidizing yellowing compounds. In theory it also improves protein skimming by oxidizing organics. If overdosed, ozone can be very dangerous, oxidizing (literally burning) the tissues of living animals. I personally would not run ozone without at least an ORP meter if not an ORP controller. If ozone is run without a controller, I would suggest running it far below the recommended level. Also, carbon must be used inline with the skimmer or ozone reactor to ensure that any free ozone gas is removed before returning to the aquarium. Ozone reactors help create large air/water interface for the ozone to dissolve and react. They probably aren't necessary if the ozone can be introduced through a skimmer.> Thanks for all the great advice and information, it has helped me through a lot of different situations. Cheers Drew <Glad to!> <<Who answered this?>>

The Ozone Connection - 07/21/05 Bob, I'm sorry to bother you with a probably stupid question. <<Only stupid when not asked...Eric R. here>> I purchased the above with a controller and hoses. I have a built in skimmer in my filter. How do I set this thing up? <<The ozone generator will have an output port that you will need to connect to the air input of the skimmer. Very easy to do with venturi-type skimmers...>> I was reading on the web site that it goes into the skimmer and then filter media with Carbon under or above filter media? <<Residual ozone is of little concern in my opinion with these and most any hobby grade ozone generator when applied through a skimmer, but many still prefer to "place a small bag of carbon where the skimmer effluent will pass over/through it before reentering the tank.">> I'm new at this hobby, tanks been running since Nov. Help!! <<Keep reading this and other such web sites, books, magazines, etc....and keep asking questions <G>...>> Thanks <<Regards, Eric R.>>

Ozonizers, proper levels 7/28/05 >...how many milligrams of ozone per hour ... sufficient and safe ? >This is the problem, Joe. Bioload. It is difficult to suggest milligrams per hour of ozone, too many variables, including bioload. To be safe, I would get an ozone generator with controller and set the ORP level at 325. James (Salty Dog)> Hi, James, Thanks for writing back. I appreciate that not all advisors have the same opinions, but I was sure that Bob had expressed opinions dismissing worries regarding ozone at least at certain injection rates. I was wondering if someone there could clarify that a bit, erring on the side of caution-- supposing one didn't have, wasn't going to have, an ORP controller. Although I could look into that if the necessity was felt to be universal... <Joe, is this going to be used in a pond? Also, does the ozonizer have settings that display approximate injection levels? James (Salty Dog)> Joe Kraska

Re: Ozonizers, proper levels 7/28/05 <<Joe, is this going to be used in a pond?>> Hrm. I found a cheap injector, not adjustable, that produces approximately 300 mg per hour. <A not-atypical sized generator for aquarium use> I'm building a pond right now (how'd ya know?), but I'll also be doing a rather large aquarium next summer. 300 gallons or so. Kind of fell into that; was doing all this research on ponds, always liked saltwater tanks (they're like art!), then became acquainted with the systemic/engineering challenges there (that, too, almost art). But my question would apply to both arenas; ponds as well as marine tanks, specifically marine reef tanks with live rock. <Could be used on either... a bit small for the/a pond use> <<Also, does the ozonizer have settings that display approximate injection levels?>> No. Joe. <Most small units do not... and not needed in almost all settings... they don't produce over-abundant O3... otherwise can be coupled with a RedOx, other monitor, controller. Bob Fenner, in HI> Ozonizers Bob, I read your column regularly and I note that you often recommend use of ozone generators, sometimes in conjunction with a skimmer. I was wondering if you could shed more light on the best use of ozone. In particular, I recently moved the ozone generator on my 125 fish only tank from the skimmer to a dedicated ozone reactor, so that the ozone now goes into a pressurized chamber to mix with the water and then the water and excess ozone are carbon filtered and returned to the sump. Do you think the generator is as effective as running ozone through a skimmer? <Probably so... but you might want to do a simple couple of tests... maybe most easily detectable with a RedOx meter... try testing under both set-ups... the higher RedOx wins... Both should work.> What about flow rates and ozone quantities? I tend to keep the ozone set low (about 15-20 meq/l) out of fear of too much ozone (I don't have an ORP monitor). Is there an ideal range and should I run the ozone 24/7? Is a controller necessary to safely maximize the impact of the ozone? <Oh. You can imagine my lack of enthusiasm for answering the above... It is way too easy for someone, anyone to seize upon such a measure per whatever... and have troubles... The amount of ozone you introduce to a system is highly dependent on many factors (Bioload, feeding, other water chemistry, filtration...)that can't be easily elucidated here (space/time)... I don't think you can get into trouble with a consumer unit... and I would run mine (do so) 24/7... and I would get an ORP measurer if not a controller...> If excess ozone makes it into the tank, what would it do? Are there any telling signs of ozone poisoning? <Elevate pH appreciably, "burn" your livestock... You would likely know... and this is very likely not a real possibility... As I say, most hobby units are too puny in 03 output to create any real havoc... the molecule is quite transient, and there are many countervailing influences in your system... to ozone excess> Thanks for any light you can shed on this interesting topic. >> Hopefully... sorry if this response is too (purposely) vague. I have a pitch about ozone stored in marine filtration articles at www.wetwebmedia.com if you'd like something possibly more satisfying. Bob Fenner

Ozonizer Following your advice I purchased a Sander Ozonizer model 25. Although I am a little confused in how to set this up in conjunction with my protein skimmer, a Precision Marine HOT-1). On the instructions it only shows hooking a pump to one end and a diffuser on the other. Where does my skimmer come in to play? What would be a good setting for a 30 gallon reef? Thank you, Rob. >> Hmm, if there is no port to hook up the discharge end of the ozonizer... feeding into the discharge point of the pump mechanism into the contact chamber: Pic here: http://www.precisionmarine.com/Venturi_Skimmers/HOT-1/hot-1.html ... then I would hook up a diffuser at/near the pump intake itself and have the pump intake the bulk of the ozone on its intake side... OR retrofit (drill) a 3/16 hole, fit a threaded/barb fitting attach a check valve or two in line and place this opening near the top... in or about the pipe/fittings coming over the tank top. Bob Fenner

Ozonizer Hello Bob, You have been extremely kind and helpful to me. Unfortunately I have yet another question for you regarding my ozonizer. I went ahead and slipped the black tubing, that has an air intake adjustment on it (from the Rio pump), to the port (on the Sander Ozonizer) that reads ozone out. I tried to place an in line check valve with/ it, but the skimmer overflowed from not receiving enough air, so I removed the valve and it is now running. Although the instructions say to place a pump on the port of the ozonizer that reads air in, is the pump necessary? Is the Rio 800 that runs my skimmer enough to siphon the air out of the ozone port? Or will I need to place a small pump to push the ozone out? I also notice their is a second black tube on the Rio that connects directly from the bottom, back into the discharge. Should I be using this in conjunction with the ozonizer, or just the one with the valve on it? See attachment. >> Hmm, well, I personally have run them with and without a pump... but I do think the pump would be beneficial in a few ways... like if there is some failure on the skimmer pump mechanism... the air pump would still "push" the O3 through the line... and as an added safeguard to curtail capillation... i.e. back-siphoning... the pump will be able to push the air and Ozone through the check valve (which I would definitely put on... an expensive day/nightmare to have the system back siphon... through the ozonizer... on to the floor.... Yikes) Bob Fenner

Ozone Hello Mr. Fenner, Do you have any suggestions in modification or otherwise using an Aquazone ozonizer with my skimmer an AquaC Remora hang-on? I thought of just pumping the ozone right into the tank, but thought it may not be a good idea. Any ideas on how I can use my ozonizer alone or in conjunction with my skimmer would be great. Thank you, Kathy <Indeed I do. At the very least I would fit a "three way" valve (with at least one check valve in line twixt the ozone generator and the line) on the discharge side of the pump, between the pump and the skimmer... with a narrowed/narrowing adaptor in diameter for the bit attaching the generator tubing to the "tee" (to act in a Venturi, entraining fashion). Better/best would be to fit all this (the skimmer and ozonizer attachment) onto a sump rather than your main tank... to allow whatever residual (it will be tiny) ozone to mix, become diluted there rather than your main/display tank. Bob Fenner>

Ozone Ick Since ozone have a very quick lethal effect on Protozoans or bacteria, why don't people take this advantage to treat Ick outbreak? <Hmm, some people do use ozone to improve water quality... thus improving their chances of preventing parasitic (and other types of disease)... but "treating" Ich this way will not likely "work" as a sole front in combating an existing/ongoing infestation> Instead of using copper for a pain taking two weeks with constant attention, Ozone need only a few minutes to practically saturate any micro organisms on the fish's body or gills. <Hmm, the concentration needed is too great... would damage the hosts as well as the parasites...> Even if the fish suffered any damage from ozone, it would quickly recover the short term trauma. <Would like to see some experimental data here... have you tried this?> Comparing to other toxic chemical ( cyanide, carbon monoxide) ozone poisoning is rather extremely short term. <Agreed... as long as in that short term it doesn't kill off the livestock...> Think of proportion: let's say when ozone is high enough to damage 10% of a fish's gills, then the casualties inflicted on disease micro-organisms are probably 100%. <I don't think this will work... but worth experimenting with...> It's impossible to be immune from disease. But can we still use the attrition war method that the BIG organisms triumph over the micro organism. <Actually, there are immuno-boosting compounds produced by some folks (like TMC on-site) and for sale (like Preis-aquaristik in Germany)... that do create pathogen free settings...> Consider the biochemistry techniques we have accumulated so far, I still couldn't find any breakthrough alternative. <Keep investigating my friend> You're right about the disfranchising of local retails of Marine Hobby. I was unaware of the biggest St. Louis Marine retails is out of business. Their livestock are too expensive and unhealthy. And those survivals in my areas don't look so bright either. <Very sorry situation... We need more good people in those aspects of the trade/hobby> On the other hand, those who love the hobby do gain massive knowledge online mostly from people like you. Give me your opinions please. <Anytime my friend. Glad to. Will you be going to the Aquarama show in Singapore this year? Bob Fenner>

Ozone Issue Hello Bob You said ozone is highly toxic to marine animals. Have you ever had any case of fatality involving fish only? <Hmm, have seen a few examples only... this is exceedingly rare... A friend had a facility in Southern California that had a huge (pounds per hour) ozone generator... and he "burned" up 350k or so "feeder guppies" (imported from Singapore during a shortage in the US)... He called me in to take a look, and the pH meter on the unit was reading close to ten... Oh, and when Chris Turk was working for Sea World (back when HBJ owned them, they likewise fried a bunch of Amphiprionine breeders... with a too-large ozonizer... but the home units that make a couple of hundred milligrams per hour... not realistically dangerous> I have some knowledge in chemistry. The living water tank is full of biological activities. Even if large dose of ozone get accidentally poured into the system, the Ozone molecules will quickly oxidize and become neutral. By the time any ozone that made it to the fish's gills, I think there would be too little ozone to do lethal damage. The air is 20% oxygen and ozone made is supposedly more less. <Agree with most all of this... but if the O3 comes in direct contact with the biota... can be toxic... but not "very toxic" in practical applications...> I know you taught high school chemistry, so what do you think? <Yes, taught chemistry and physics... Do use ozone, install corona discharge and UV type generators at collecting stations all over the planet (and desiccators for the air entering them)... am a big fan of ozone use... Bob Fenner>

Good time to hook up the ozonizer??? Bob, My 240 has been up and running for 4 weeks now. It has a underneath wet dry filter with bio balls. and a AquaMedic skimmer in the sump. My question is should I wait another couple of weeks before hooking up the ozone generator?? The reason why I ask is that I'm afraid that maybe my bio balls in my wet dry hasn't matured 100% yet. I tested the water no ammonia, no nitrites, and only 25ppm of nitrates. What do you think. Will running ozone interfere with my biological filtration? Keeping it from 100% maturing?? Thanks again, your fan. <At this point, you could start the ozonizer or if you feel "uncomfortable" no worries in waiting a couple of weeks more... suspect your system is already "cycled"... Bob Fenner> Livestock XL Vlamingi tang Lg panther grouper lg miniatus grouper lg Naso tang sm Atlantic blue tang sm blue lined grouper sm Huma trigger 120 lb Liverock 200 lb aragonite coral sand. Non living.... Lee

Ozonizer Problems!! Hope you can help me with my problem or steer me in the right direction. Several months ago I purchased a Clearwater S-1200 250MG/hr Ozonizer to be installed as part of a system which consisted of a Berlin Turbo Skimmer and that Ozonizer. I got this system working and the ozonizer was effective increasing RedOx (up to 400mv!!) and all was well. <Sounds a bit high> Several weeks ago, I commissioned a local, highly regarded aquarium store that also specializes in professional systems installation and maintenance, to install a chiller and "re-engineer my system if necessary. They strongly urged me to replace my Berlin with an ETS counter-current skimmer (Super Reef Devil). <Hmm, why?> The switch to the new skimmer did not allow me to use the ozonizer since this skimmer was not designed to "suck in" ozone and provide enough contact time for this process to be effective. <What? The ozone could/can be entrained through the air intake area of these downdraft skimmers... Or be pulled into most any water flow conduit through an air pump, Venturi... > I actually tried hooking up the ozonizer to the "air intake" of the ETS skimmer and it not only didn't increase the ORP level, it also sent me to the doctor with a very bad headache!! <Bizarre> I spoke to someone at Clearwater who BELIEVED that I could use a High Pressure air pump like a Tetra Luft or a Rena and push air into a reaction chamber. He was going to research this and get back to me but he never did. <Can be done> I located an old Lumar OXY-415 Reaction chamber which is about 16" high with a diameter of 4", a 0-15psi pressure gauge, 1/2 fittings and an air-tight design. My installer came over yesterday and installed a Penn-Plax silent X6 fed into the ozonizer (250 mg/hr) fed into the air/ozone inlet of the Reactor. Water is being pumped into the reactor at 180 - 250 gallons per hour. We hooked everything up yesterday and the process failed to work properly: 1) The pressure on the Chamber could only be "ratcheted up to about 3/4 inch of PSI. <About all this pump will do> 2) The ORP barely moved up to 270 from an initial 260 reading, indicating that the process was not working. When this ozonizer was working with the Berlin Skimmer, the ORP would go from 230 to 375 in less than 2 hours!! 3) I got up this morning with a headache and eye irritation. The room smelled from Ozone and I had to pull the plug in order to get things back to normal A couple of possibilities; First, the reactor is not creating enough contact time for the ozonizer to work to any degree. Is that possible?? <Not likely> Second, the pump I'm using, albeit a high end diaphragm pump, just doesn't have enough pressure to create a good pressurized system. I assume one of the keys to this process is to have some pressurization, albeit small 2-3 PSI?? Is that possible?? <Yes> I'm really very frustrated and almost ready to throw in the towel! I probably should have left well enough alone and kept the Berlin Skimmer <This is exactly what I would do... Dump them and the new skimmer arrangement... Go with what you know, and what works.> but my aquarium folks strongly urged me to switch to a "21st Century method of skimming". <What? I don't agree with the statement... The Turboflotor product is far better engineered, constructed... is vastly superior efficiency and technology-wise. Query other sources for their input here.> I'm also thinking that I might just want to put an inexpensive AMiracle Venturi skimmer in the AMiracle SL250 Trickle filter sump just to facilitate the ozonizing and let the other skimmer do all the "dirty work". Your thoughts?? <Could be done... but I would just go back to your working gear> Any help you could give me would be greatly appreciated. I believe in Ozonizing and don't really want to give it up. <I believe in "success" by whatever means... and your (and everyone else's) capacity, even duty to "make up their own minds"... Don't rely on reputations... Decide for yourself> Thanks in advance for any help you can give me Sincerely Lewis M. Kirschner <Be chatting, Bob Fenner>

Ozone Hi Bob, Thank you very much for your website and countless pages of valuable info. I've read the sections on ozone (and numerous other pages) and couldn't find the answers to these questions. I hope you have time to answer these. I really value your experienced judgment. Thank you very much in advance. I broke down a purchased a Red Sea Aquazone 100 ozonizer with ORP controller. If I connected this to my Turboflotor Multi skimmer directly (with check valve) do you think the Venturi effect of the Turboflotor pump would produce sufficient draw of air without the need for an extra air pump? <Possibly. Have done this sort of arrangement with other ozone, skimmer units. Easy enough to test... changes in water quality... w/o O3 being on, and pump for air in use and not...> Could the "air dryer" be a Chinese soup container with desiccant in it and appropriate vent holes? <Yes... take care that if you're using a potentially (human ingested) desiccant that it not be consumed by small children, pets...> What exactly is the desiccant material? <A chemical that selectively absorbs moisture/water> How much of this material would be appropriate for a 110 + 30 gal. sump? <There are many types... with varying functionality... and depends on how much moisture is ambient, how much air will pass over/by the drying agent... Do use your search engines here> How often do you think it (the desiccant) should be changed? <Varies per the above criteria. There are even physical dryers made for aquarium use...> Finally, my plumbing (supply & return lines) in the cabinet is vinyl flexible tubing of various sizes from Home Depot. I have asked everyone I can think of if it is ozone resistant and no one knows. Do you think clear vinyl tubing is ozone resistant? <Only to a degree. There are "more ozone" resistant flexible conduits... they may be more expensive than just periodically replacing your current polyvinyl lines> My local fish stores only sell small air-line ozone resistant tubing. I'm sorry for all the questions but being new to the game I just don't know. Again, thanks a million! I'm looking forward to your next book. <Thank you for your writing, inquisitive mind. I do wish folks of your curiosity and drive were more part of our industry. Bob Fenner>

Ozone Hi Bob <Hello> I have another (mercifully short!) question for you. I adopted your refugium idea in the middle section of my sump where I now keep a 3 inch oolithic sand bed, some live rock, Caulerpa and Sargassum. I works like a dream! <Ah, good> I have an 80 gallon reef system with a 20 gallon sump. I have been thinking about getting an ozonizer once the tank is fully stocked and injecting this straight into the Berlin Classic skimmer. The skimmer is located in the first section of the sump and discharges over the divider into the second section which houses the refugium. Assuming I adopt a conservative approach to ozone use, say no more than 25 mg/hr, and the skimmer is not releasing any (or too many) bubbles into the refugium, is this viable or will I kill every copepod etc. in there? <Will be fine... even if/with a few times this much O3 per hour... mostly "used up" in contact/or of unit... Bob Fenner> Thanks again Simon Sleigh, Manchester UK

OZONE in Large Tank Holding Mr. Fenner, Our company specializes in live seafood holding systems, incorporating screening, BioFiltration and protein skimmers along with a well-distributed flow at a good rate through the tanks. We have concentrated on shellfish, and are being asked to do fin fish systems. Ozone is requested/ required in some cases. We plan to add the ozone at the skimmer(s) for best effect. I have 4 questions. 1. In systems of 1000 gallons or larger, should the ozone applied be based on flow rate through the treatment unit (skimmer) or based on the total system volume? <Mmm, both and with consideration to the bio-loads... it would be better/best to have a variable/adjustable ozone generation, delivery system... of a few gram per hour capacity... and a desiccator...> 2. If flow rate as I suspect, what dosage is appropriate for flow based on multiples of 25 gpm? <To be discharged where? Into the main system? Better to couple this ozone source with either RedOx, pH metering in the main system... throttle up/down per load...> 3. From reading the Ozone FAQs, I conclude there is no significant risk of toxic carryover from a protein skimmer, particularly if the skimmer discharge is into a treated water reservoir or otherwise vented before getting to the holding tank. Is there reason to consider some carryover prevention process or to ensure a certain time delay before using treated water? <Not much danger here in practical "pet-fish" application. Some greater/graver concerns in your circumstances with larger generator, varying bioloads... as I say, do utilize a meter, switch...> 4. Is an ORP or other sensor recommended to control the dosing rate in this size of system? <Oh! Yes> Thank you for your assistance. Your comments and insights are extremely helpful. Roy Hobson, Tech Sea 2000 Inc. <A pleasure and honor to be of service my friend. Bob Fenner>

Re: Ozone question? I am a little unclear on how to filter return water directly into my main skimmer for my central filtration unit. I hope this is not a dumb question. <Not as far as I'm aware, concerned. There are a few ways with such a large system, flow-rate as you describe.> I am not much of a plumber. I would think that water flow would be a little too much. I will have a 480 gallon system. I would like to circulate the system water 5 times. <I would likely first have the water run through the bags sold by Emperor Aquatics (there are others) into a sump of constant volume, overflowing into another area of the same constant level (with partitions going under in the first part over a weir in the second... and have the skimmer run in from the first out into the second... to facilitate its operation, efficiency. You could/would do well to add ozone here or directly into the skimmer... perhaps even investing in a desiccator to dry the incoming air into the ozonizer. Please do read through the set-up sections re gear on the Marine and Business Indices on our principal site: WetWebMedia.com here Bob Fenner> I hope all is well!

Ozonizer Bob, Is it ok to keep my skimmer, and ozonizer on, when medicating main system, with chelated copper? <Usually better to leave these off. Both tools can effectively remove the copper compound.> I got a little outbreak, of Ich. and I want to keep the tomites in check. <A toss-up, consideration of whether you consider water quality more of a benefit to ward off infestation or the medicant> My tanks a 240 gallon FO. With only 3 show size fish. I have a RedOx controller , and the ORP is set at 355, but my ORP in the tank is 220, Imp currently inj. 120 mg of ozone. Should I increase dosage. My ozone gen, can pump up to 200 mg of ozone. <I would try this... and likely look into switching out some substrate, or better, adding live rock... cleaning your skimmer... to increase RedOx> Should I increase dosage, to try and bring up the ORP??? And if yes, how much more should I inject. <For me, all... for safety's sake, an increment of tens of mg/h and see if there is a response in ORP reading> The ozone gen. that I have is a Red Sea Aquazone Ozonizer plus, Meaning with ORP probe, and RedOx controller. Thanks again, Lee <Be chatting. Bob Fenner>

Ozone, and reading RedOx hi Bob, I just purchased a Red Sea ozone gen. with a ORP monitor/probe and RedOx controller all in one. This model puts out 200 mg of ozone. Anyhow my system is a 240 gallon FO , with only 3 XL fish. Anyhow my current RedOx is 200-220 range. I want to bring it up to 350. So far Imp injecting 120 mg/hr of ozone into the system. The RedOx seems to be at the 200-210 range. I know the RedOx can vary , depending on the tank conditions. Example feeding your fish, putting your hand in the water. Anyhow Do you think I should raise the ozone amount? Will raising the ozone amount bring the RedOx to a higher level quickly?? Thanks again, <Already answered... I would "experiment" raising the ozone output to see the resultant change in oxidation reduction potential... Likely you cannot generate too much with the gear, set-up, livestock mentioned. Bob Fenner> Linstun

Ozone Bob, Another ozone question. My ozone unit will pump out 200 mg, of ozone. It has a RedOx controller, and probe. You can adjust the unit to the desired RedOx, and it will shut off automatically when the desired RedOx is met. Why cant I just crank up the ozone max 200 mg/hr?? <Why not?> My tank is a 240 gallon FO. Isn't the important thing is keeping the RedOx at 350-400?? <Mmm, "important thing"... I would think this is actually keeping the system viable, stable, optimized...> So if I cranked my unit 100 percent. Wouldn't my RedOx go up quickly to the desired range? <No, not quickly, likely not at all... try it and see> Because I read that you shouldn't put more than 15 mg/hr per 25 gallons of water. I just thought that monitoring the RedOx is the key, and not worrying about how much ozone you can crank. <Many factors here besides delivered rate...> Oh, another thing, you mentioned that hobby units were not dangerous. One of my hose popped out over night, and my whole living room smelled like ozone. Is that really dangerous? <Once again, depends... how sealed up is the house? How large?... Not likely dangerous.> and my last question. I was reading in your FAQ section on ozone. You mentioned to one aquarists to buy a electronic ozone device, and not one that produced it through a corona discharge, why is that? <Perhaps need for larger amounts of ozone> My Red Sea ozonizer utilizes a special high-frequency process instead of a electrical discharge. Is that good? Thanks again' <Sure... this is a corona discharge unit. Should be fine. Do study what ozone is, its applications... through college book reading, the wider Net. Bob Fenner> Lee

Re: Dissolved Oxygen follow-up Anthony, Hmm, using an ozonizer on a quarantine tank, Heh ? <a logical treatment in an appropriate place> Are you recommending using an ozonizer injected into the skimmer or some other reactor into the quarantine tank ? <affluent must always be passed over carbon... I like running it through a skimmer> For instance on a 40 gallon quarantine tank I have, using a Remora Pro, you would inject straight into the remora (have to figure out where for that unit would be best), or via another method. <always check to see if your model skimmer can take ozone... the better made units with stable plastics will tolerate ozone... to be injected through the Venturi or other air inlet to main chamber body> The other issue is that if you have a problem with a specimen and move it to a hospital tank. I generally don't use skimmers in my hospital tanks as I prefer hyposalinity vs. meds for C .irritans (most common parasite encountered with new fish), and skimmers are extremely ineffective (no skimmate) at low saline levels. <I disagree with extremely low salinity treatments. As such... a "lower" salinity approaching 1.017 will still be fine for skimmate production. Even if it didn't... the skimmer can be used simply as a chamber> If you injected ozone via the skimmer, that option is no longer available. . . <I don't see why not but it is your call. Please do help yourself and review the archives. Bob and other crew members have different opinions and perspectives on ozone. Perhaps the consensus will help you with your decision. Anthony>

Ozone/Crypto Just curious, I know ozone 'oxidizes' a bunch of stuff and if it comes in contact with living organisms, its generally not good. Wondering, is it useful in fighting crypto ? In other words, if free swimming (or cysts) are sucked into the skimmer and ozone is present, does it kill them as well ? <Am sure it does weaken, if not kill these stages> Also, how is ozone effective if its only on partially? <Mmm, partially... not a good/evil sort of didactic world> It appears that the ozone reaches a certain ORP level, and then stops. If your ORP stays at that 300 level, the ozonizer never turns on. Is it then the ORP level that is 'good' or the ozone itself that is 'good'. Thanks <Both... Oxidative Reduction Potential can be elevated, raised beyond the "300" level, can/does become dangerous to life much higher. Bob Fenner> Jim

Re: Ozone question Thanks for the response. As a follow-up, I know ozone is excellent in a quarantine setup as ozone pretty much wipes things out on contact (including ammonia, nitrite). Anyhow, what if you have to dose with copper. What happens with copper in ozone ? <It is much more readily precipitated, removed from solution at practical/high ozone levels.> Can you use ozone when treating a fish with copper for parasitic diseases ? <Not in general> Also, if you can, there is the issue of the carbon. Carbon is needed to filter out the ozone, but it'll also screw around with your copper levels. Is it better to just turn the ozone down to 50mg/l (110gallon tank) and not use carbon to remove trace amounts of ozone (a bit risky, but probably safe for the amount of ozone being used), as that will also remove the copper in solution ? <A worthwhile approach. Bob Fenner> Thanks Jim

Curing Live Rock/Ozone Curious question. Since I know its a good idea to run a skimmer while curing live rock. What about pumping a bit of ozone into the skimmer during the process with one of those small Aquazone (I have one handy). It'll neutralize the ammonia/nitrite immediately. So I guess the benefit is that more organisms/corals that are on the rock will survive since the water conditions are better, but less bacteria will develop. Is that the trade off ? <More of the former benefit, less bacterial generation from decomposition en toto> I guess the basis would be that if you are 'cycling' a tank, you shouldn't do it this way, so you get as much bacteria developed, but if you are just curing rock, then I imagine this would work fairly well ? Am I way off base, or does this sound right ? Thanks <You, one doesn't want "those types, amounts" of microbial activity, pollution if can be easily avoided. Better to utilize the ozonizer, have better water quality through this process. Bob Fenner> Jim

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