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More FAQs about ORP, Ozone, Ozonizers Use/Rationale

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 FiltrationRe-Dox,

Related FAQs: Ozone, Ozonizers 1Ozone, Ozonizers 2 Ozone 3, System/Selection, Application/Installation, About Dryers, MeasuringMaintenance/Repair, Reduction Oxidation, & Marine Test Gear 1, Marine Test Gear 2, Marine Water Quality, Marine Water Quality 2, Marine Water Quality 3,

Is the best, better water "worth it?" Clavelina diminuta Kott 1957.

Hair algae-Second send, smaller pics      7/8/15
I'm going to apologize in advance for the length of the email, but I did want to make sure I gave you every detail possible.
<Real good>
I have been combating hair algae for approximately a year now.
<No fun!>
Here is the current stock and tank information.
180 gallon reef tank 72in x 24in x 24in, 80 lbs live rock, aragonite substrate
<Mmm; well... let me comment as we go along. I'd ditch the Aragonite... see WWM for rationale and alternatives>
30 gallon sump
<Oh! What do you do with this sump? I WOULD have a DSB here, RDP macro-algal culture>

Livestock, inverts, corals: 2 black and white clowns, 2 ocellaris clowns, mandarin dragonet, royal gramma, orchid dotty back, lawnmower blenny, azure damsel, 5-pincushion sea urchins, purple Linckia starfish, peppermint shrimp, handful shrimp and snails
Zoas, Palys, hammer/anchor, star polyps, mushrooms, Sympodium, candy cane, rock anemone, rose bubble tip anemone, Acan (not doing so well)
<Likely it's losing to the Zoanthids and more... Better placed elsewhere>
Livestock fed about once a week-
<I'd increase this with smaller feedings to at least every other day... if not daily>
frozen and freeze dried mysis, salmon roe(Asian market sushi), new life spectrum. Stopped frozen stuff about 3 weeks ago after realizing the perils of not washing
Coralife 2900 powerhead installed a couple weeks ago (prior to this Koralia 1400)
Hydro Koralia 1500
Kessil 360w x 2
one cheap recycled LED with just the actinic being used
Reef Octopus Classic NWB 110 in sump skimmer(I know this is under rated for the size of the tank, clean out grime weekly)
Homemade phosphate reactor using PhosGuard introduced about 2 weeks ago(prior to this phosphate was at 1.0)
Auto top off with unsalted RODI water
5 stage BRS RODI with chloramine for source water; filters changed about 2.5 months ago, but prior to that had not been changed in a while(well passed what they should have been).
Seems like problems with algae started shortly after a major tank wipeout from ich.
<Am wondering what your RedOx is here... I'd bet low; under 200 uS/cm.>

Left tank essentially fallow(no fish or coral) for about 3 months or so.
Started reintroducing fish and coral shortly after algae started. Measures taken-removed all substrate(typical sand) and switched to aragonite and rocks scrubbed about 3 months ago. Tank looked good for about 1-2 weeks
and then algae returned. I've bulb suctioned and manually removed the algae with water changes. Water changes about 10-20% every week. Current levels as of two days ago with water change were
kH 5.7
<Mmm; low... s/b 7-9.... the higher value better>
alk 2.05
<Better higher.... I'd shoot for 4 meq/l>

Nitrates 0.2
Phosphate 0.25
Calcium 500
<Too high... I'd keep under 400 ppm>

Mg 1410
<And this in proportion... about 3X>
pH 8.2-8.4
RODI water nitrates and phosphates negative
<The above two mighty fine>
I've included some pics, taken two days after a water change
<Bunk and gunk!>

Again, apologies for the lengthy email. Thank you so much for your help
<No worries... you see my suggestions above? Dump the gravel, mod the sump/refugium (add sugar fine DSB of 10 cm/4in plus depth), macro-algae of use; lighting on a reverse photoperiod....); increase the feeding interval;
time going by.... and Wham! All fixed. Bob Fenner>
Re: Hair algae-Second send, smaller pics      7/8/15

Bob thank you for your quick response and expertise. After your response I tried to find all the articles about the RedOx and dsb/macroalgae use so I didn't ask a bunch of already answered questions,
apologies if I didn't succeed. I'll decrease calcium and magnesium, increase alk/kH. Would you actually recommend measuring RedOx level or just treating empirically by adding Caulerpa?
<Am a HUGE fan of measure; and if practical, manipulation (w/ 03 admin.) of RedOx... ALL public aquariums and bigger wholesale; many retail facilities avail themselves of this useful tool/window into biological fitness of systems>
I'm running into a little bit of confusion regarding the substrate. From what I am reading(please correct me if I'm wrong) the issue is more with the size of aragonite and not the aragonite itself.
<You are correct; though many "aragonites" trend to be more calcite/insoluble than useful period>
I will add a sugar fine dsb into a section of the sump along with macroalgae. Is your preference Caulerpa or a variety?
<Please read here re: http://wetwebmedia.com/refugalgfaq2.htm
Am decidedly against the use of Caulerpaceans nowayears; instead push species of the genera Gracilaria and Chaetomorpha>
Whatever the substrate is would you recommend the display tank have sugar fine as well?
<Mmm; yes; unless you're stocking some organisms that can/will use other... >
So after correcting all of this will all the algae dying off cause a spike in nutrients and if so will normal water changes be sufficient or will manual extraction be needed?
<Indeed it will>
Thanks again for all the help
<Thank you for your intelligent, patient involvement. BobF>

Re: Hair algae-Second send, smaller pics        7/9/15
Okay I'm eyeballing the Milwaukee ORP tester on bulk reef. As far as treating with ozone, are the human health concerns reasonable and likely
<No.... as gone over and over... on WWM, books and articles I've penned... get/use a unit (ozonizer, likely a corona discharge unit) that only produces a few mg. of 03 per hour... No human danger>
(have a 13, 8 and 3 year old)? I went ahead and got some Chaeto and Gracilaria from LFS and put it in sump with LED lighting. They had CaribSea aragonite Aragamax sugar size oolite-would this be acceptable?
<Ah yes>
Thanks again for your advice
<Welcome. BobF>

Re: Hair algae-Second send, smaller pics; Ozone/RedOx       7/19/15
Bob I received my Milwaukee MW500 ORP meter and you were spot on. ORP read at 11.
<Yeeikes! Distilled water, milk, or dielectric oil used to fill submersible pumps!!!>

Thoughts on such a drastically low ORP?
I'm planning on installing an Ozotech Poseidon 200mg/hr 30281 aw-blk and using a Milwaukee mc510 (wish I would've got this in the first place) to control it. Please correct me if I'm wrong, but from any info I've been able to find it appears the two can communicate with each other.
<Should be able to. Contact the manufacturers of both if a problem>
Based on the crews previous comments it looks like both units are typically on the preferred lists compared to other devices, does this still stand true?
Thanks again for your insight
<And you for your participation, sharing. BobF>

Fish Room. Design and Ozone use        4/9/15
Thanks so much for your reply about the ammonia issue in my fish room.
I've taken your advice, and in my search for a larger protein skimmer and fluidized filters, had a long discussion with someone from a reputable company which also sells ozonizers, and he highly recommends one (in conjunction with a good protein skimmer), as one of the steps to help with my ammonia and nitrate issues.
<Ah yes; a worthy, worthwhile piece of kit... next, a dryer for the ozonizer>
So my question is (and I think I know the answer after reading some of your posts on it)..........would you recommend ozonization for my fish room, and if so, would you recommend a central unit which I could use for all five of the systems in my fish room, and then just put an orp controller on each of the systems (about 3,000 gallons of salt water total)?
<Yes and yes>
Thanks for your input.
<Ahh; as always, just stating what I'd likely do given the circumstances presented. ALL public aquariums and wholesale facilities utilize 03. ALL stores and holding systems I've been involved in design and operation as well. Bob Fenner>

Ozone sizing (using) question      1/8/15
Hi wwm crew,
I have a 155 bow front tank with a 38 gallon sump. I just had a bad battle with velvet and returned my remaining livestock to a 55 hospital tank. I'm leaving my tank fallow for 8-9 weeks and treating my 55 hospital with copper power. All of my live stock was quarantined for. 8 weeks prior to hitting the display. My question is regarding ozone sizing. A friend offered his ozonizer rated for 55 gallons . Will this provide any benefit whatsoever? Or would it be a waste of time?
<O3 administration can definitely be helpful in aiding in improving water quality, raising RedOx, O2 conc... reducing TBC, other microbial population... This is all gone over, archived on WWM>
I'm going to add either a uv or ozonizer
<The former can/does much of the latter, again; READ on WWM re>
for better water quality prior to my fish being returned to my display.
I'm just looking for sound advice and you guys are the place to get it.
Thank you for all you do!
<Cheers, Bob Fenner>
Re: Ozone sizing question      1/8/15

Thanks for the fast response Bob. I've read quite a bit on www regarding ozone/uv and feel ozone would be more advantageous. My concern is the small unit I have available. It's only rated for a 55 gallon tank. Would that benefit my system at all or should I buy a larger one?
<A little ozone addn. is better than zip; and def. better than too much.
Don't have time, desire to re-key admonitions re... nor advice re measuring RedOx. BobF>
Thanks again,
Re: Ozone sizing question      1/8/15

Thanks for the insight. Happy new year as well
<Ahh; to you as well. B>


I'm wondering about using either an ozone generator or a UV system to help me keep on top of potential disease.  Which would you use and what are the benefits of either.  If I get an ozone generator do I need a controller for it?  Please help it's all so confusing.  Thanks.

James Wilson, Bath 

This will have to be a greatly foreshortened explanation to what could be a very long explanation James. Both types of water filtration gear will indirectly help w/ reducing the pathogenicity of disease causing organisms'¦ through improvement in water quality. 'Some' well-engineered ultraviolet sterilizers that are fitted with proper flow rates are able to 'zap' small organisms (bacteria, fungi, perhaps some Protozoans) sufficiently to kill them outright; all do some good in producing ozone (O3) to a degree. There are Ozonizers (ozone generators) that are actually ultraviolet lamps, though most in our interest are corona discharge types.

            Ozone generation by itself is a great sanitizer of water, increasing dissolved oxygen, increasing RedOx, helping to resist acidification and all its related downsides (unavailability of alkalinity, alkaline earth materials'¦ i.e. Calcium, Magnesium, Strontium'¦). This technology is such a boon that there are NO commercial aquariums, marine livestock wholesalers, or aquaculture facilities of size that I've been to that don't employ it. In fact, given the choice of UV or Ozone, not only would I take the latter, but the next choice would be a desiccator (to dry out the air going into the Ozonizer) than a UV in turn.

            Rest assured, you are not alone in your confusion. The variation in the utility of this gear, its appropriate application, and attendant possible beneficial effects are subject to a myriad of interpretation. Both will help in a few ways, but Ozone is my greatly preferred (over UV) adjunct to an otherwise well-filtered system.

            A controller for the Ozonizer is not really necessary'¦ IF the unit is sized about where you want it and 'oxidizable materials' are about constant (not hard to do). Even small (hundreds of milligrams of O3) ozonizers have adjustable dials for output'¦ with simple measure; one can get close to what the constant output should be.

New system equipment - question... Sump skimmer sel., ozone use    1/22/12
Mr. Fenner,
     I am newbie to marine aquariums and reef systems. In an attempt to get educated before purchasing and setting up a system I am reading your book, The Conscientious Marine Aquarist 2nd Ed. in preparation for building my first marine reef aquarium system.
<Ahh; I know you will gain from its perusal>
 I plan to keep fish, invertebrates and soft corals. I wanted to get your opinion on the best in sump protein skimmer I can get for around $300 - $400?
<Mmm, for a 75 gallon mixed reef now and who knows what down the line...
There are quite a few choices; as you can read re here:
For ease of maintenance... I am still a fan of Aqua-C's line>
My display tank is going to be 75 gallons. I plan to have a 29 Gallon sump - refugium with live rock.
<Mmm, anyway to fit something larger?>
I was looking at the Super Reef Octopus 1000 internal.
<Also a good unit, make>
 However I did want to get a skimmer that is compatible with ozone use. As you mention in your book that ozone increases a skimmer's efficiency.
<And has many other substantial benefits>
 I was told by the CoralVue people that in their opinion it would not be best to couple ozone use within that skimmer as the chamber was too small for anything significant to occur to increase the efficiency and they recommended first of all waiting till I had more experience and then using a totally separate ozone reactor.
<Good advice>
Also, in their opinion using ozone will not increase the efficiency of the skimmer.
<This is non-factual>
I am confused. What do you think about this?  Also what type of ozone system do you recommend?
<There are a few variations to be considered... Please review here re an overview: http://wetwebmedia.com/redoxinst.htm
and the linked files above and on sites like ReefBuilders.com re recent events>
Thanks for your book and your advice,
David LaRocca
<Certainly welcome. Bob Fenner

Ozone Questions... reduced algal growth effect, placement of ORP probe 8/27/11
Hi guys
<Hello Matt>
As usual you are my first port of call when it comes to my fish dilemmas!
Firstly, I have been running ozone through the skimmer in my sump for several months now and have noticed a significant decline in the growth of desirable algae in the sump (Caulerpa primarily); is this to be expected as there will be less organic compounds for them to feed on?
<Is the whole idea.>
Also I am seeming to have to clean the probe tip on my ORP meter daily in order to get accurate readings. It seems to keep getting gunk on it which lowers the readings. It is in the main tank in a 'quiet' corner, should I place it in a higher flow area? Is this a fairly common issue?
<Best to place in the sump, away from a light source and where water is moving.>
Thanks so much as always.
<You're welcome. James (Salty Dog)>

Treating A Stress Ich Outbreak With Ozone 10/3/10
Hi All
<Hello Jim>
Jim from the UK here. I am getting back into reefing after a long pause (I have kept fish /invert tanks for 5 years prior). I have set up a new 120 gallon system and cycled with cured live rock and Tetra Marine Start.
My first fish were clowns (added after a 2 week cycle) all parameters were normal.
<I hate that word "normal". Knowing actual is much better.>
They are a very nice pair (proven pair) of Bicinctus Red sea clowns.
They seemed to settle down fine but after a couple of weeks I had a minor outbreak of Ich.
I have decided to invest in an ozonizer this time around and am currently doing a medicative dose of 75mg/hour
<No such thing as a medicative dose. Too much ozone can be dangerous to the inhabitants if not administered safely. Is best to use a ORP monitor or better yet a RedOx controller. A good ORP level would be 325-350.>
into my skimmer plus I am also using garlic infused feeds. Mr. Fenner your books are an inspiration to me and you may castigate this seasoned pro because I freshwater dipped the clowns prior to addition to the main tank. I didn't quarantine; feel free to tell me off.
I am new to ozone addition but have read that it has very good anti-parasitic qualities (the dosage was recommended to me by the LFS).
<The ozone will only kill the parasites that come into contact with it in your skimmer.
Ozone does provide for much better water quality which helps the fish fight off parasitical infestations much better.>
The clowns are seemingly on the mend and was wondering how long I should keep up this dosage of ozone? 2-3 weeks?
<Actually, continued use of ozone is very beneficial to the health of a system and I would use continually but to at least monitor with an ORP meter and ideally, control with a RedOx controller.>
I am stringent with water changes and there are zero nitrites and ammonia in the tank. I see this as a minor territoriality/upset between the mated pair. <?>
Many thanks,
<You're welcome. James (Salty Dog)>
Re Treating A Stress Ich Outbreak With Ozone 10/4/10
Hi again
<Hello Jim>
Many thanks for your reply.
<You're welcome, and please reply to original thread in the future. Gives me an idea what has transpired so far.>
I will consider investing in a RedOx controller but for now my stated dose 75mg/hr is only slightly above the recommended dose by the TMC unit, so I feel does not need monitoring just yet.
<You are correct, is slightly higher than the 25mg/50 gallon recommendation.>
I have considered a UV steriliser but find they do raise my water temperature into the mid 80's.
<Much, much better off with ozone.>
Clowns do not seem to have any ICH spots now so I am hoping this is a settling in outbreak. Do other tank owners find this with new clowns (more so with wild paired clowns)?
<Tank bred clowns are generally hardier than the wild caught.>
I know they are wild caught and as such are more susceptible to disease so I hear. I realise I have broken the quarantine tank rule but I have found that with dips and keeping water quality/species interaction at an optimum, that I avoided all disease problems in my previous tank, but did have the occasional Ich outbreak when new fish were establishing territory.
<No guarantees. James (Salty Dog)>
Ich outbreak after trigger addition, vis a vis O3 use for Crypt prev.
Hi All
<Hiya Jim - Darrel here>
Your thoughts as ever very welcome and well received.
<Ok, well, you're going to get some. I'm copying the Boss who may have a thought or two to add><<>>
Jim your UK aquarist here. I recently wrote about using ozone to assist in the defense against ICH. Well sadly after I added my Assasi trigger to my main display tank the two red sea clowns have a dusting of white spots again, as well as the trigger himself. There are territorial disputes (mainly at lights out when finding a place to sleep) which are evident by the large female shrouding the(half her size may I add) the trigger and dominating him. The male sort of joins in and the trigger semi puffs up but generally seems unfazed.
<The territorial disputes are normal and to be expected. The Cryptocaryon - not so much>
The fish feed well and don't appear to be breathing heavy or in any stress,
<But then, every infestation starts out with a few spots, don't they? Then they build from there>
'¦ the Ich is not what I'd call a major infection.
<But then again, another term for major infection can easily be the death of some fish><<It will be>>
The small male clown flicks occasionally but the Ich infestations do seem to die off after a few days when these disputes are resolved and regular feeding continued.
<Well, one theory that many aquarists share is that crypt, like the common cold, never goes away completely - but that healthy fish in a healthy system simply tolerate the few parasites, essentially shrugging them off, until or unless that fish gets debilitated in some way that allows the infection to take hold. If that is the case, the fish may show increased susceptibility during times of disputes. That said, the general experience in the hobby is that once they get a foothold, they don't ever just "go away" like you're describing>
I don't quarantine (yes I know it makes me a pariah). In the past as I've stated I have overcome every Ich infestation with strict water changes and vitamin/garlic soaked foods.
<Water changes are a well established technique for dealing with the free-swimming Tomites before they find a host. To me, the logistics of changing enough water with enough frequency to remove enough Tomites to actually affect the course of the infestation is daunting. Running the water through a higher wattage UV sterilizer and/or exposing a large flow of water to Ozone would seem to be less of an effort on your part and less stress on the fish, as well.>
<I also use Garlic to treat my fish and it {quote}SEEMS{quote} to work, especially with surgeonfishes '¦ but I'm unaware of any scientific basis for that belief. For all I know it could be something that just keeps me occupied while nature runs it's course, but like any religion or superstition of any primitive culture, we aquarists learn what we think we learn and stick with our beliefs for decades>
The ozone is backing up this theory I feel and while it doesn't let me off the hook with quarantine I know, I have to feel that more stress is caused by netting/hospitalizing/copper treatments than allowing a dispute to resolve and provide optimum environmental conditions to the treatment of this annoying parasite.
Your thoughts as ever very welcome and well received.
<Really? Well here are my thoughts:>
<It seems to me like an awfully mean thing to have done to an established tank with healthy fish.>
<It seems like bringing a person with H1N1 Influenza into your house and telling your family that after everyone adjusts to the new family member and at the same time recovers from the flu - then we'll all be happy. Unless one of us dies. Then not all of us will be happy.>
<Whether the stress of the disputes is causational in the Crypt outbreak or incidental, you're asking the fish to fight for their place in a disrupted natural order at the same time they're fighting a life threatening disease.>
<And you're doing this because it is too much trouble to place the Trigger in a separate tank for 6 weeks to let him get accustomed to your water and climate and to identify any potential diseases that he may have? And this is ON TOP of perhaps 4 or 5 dozen diseases, contagious and otherwise, many of which science has not yet identified that can be fatal to the new fish and others to which he has been exposed?>
<Jim, you say that not quarantining makes you a pariah. To be perfectly honest, Jim that is NOT the word that comes to my mind, but this is a family site>
<You asked for thoughts and those are mine. I do not, however, speak for Bob Fenner or Wet Web Media -- both of which, I'm sure, are grateful that I do not>
<Bob? Please correct me?>
<<I don't find anything factual to correct or profitably add Darrel. I do consider that Ozone might play some indirect roles in limiting diseases of various sorts, but I don't think its use, by and of itself will prevent infestations from spreading, nor cure extant ones. I would add a general link to our/WWM's Cryptocaryon archives: http://wetwebmedia.com/mardisindex.htm
scroll down... BobF>>

UV and Ozone 2/23/2010
Thanks for your invaluable advice. I have a fish only Caribbean only biotope <Nice!>, moderately stocked (once fish reach mature size I'll consider it heavily stocked), artificial corals. Sorry, not a reefer and not planning to add live rock, either. I like the look I've got.
Display is 310g. 150g sump in basement has filter socks from overflow, biotower with bioballs, UV, skimmer.
<This sounds like a nice system>
System has been running 18 months, has finally stabilized, no livestock loss or additions in last 3 months or so. I recently added 200mg/hr ozone to skimmer and have seen marked improvement in water clarity.
<Yes, this is what I would have done. I do think Ozone comes under the 'marvelous' banner!>
My question--has the UV sterilizer become unnecessary/redundant now that I'm running ozone?
<I think so. I am not a fan of UV really, just too much maintenance for too little benefit IMO.>
I wouldn't mind removing one pump and bulb from my power hungry system.
<yes, I would go ahead with this course of action>
Thanks in advance, -Mike
<Pleasure, Mike. Simon>

Ozone/skimming Q/clarification? 6/16/08 Bob- did you ever say that ozone is more important than protein skimming? <Might have... is in many situations/set-ups> An aquarist or two on the MD web forums are discussing this tid bit (they claim came from you), but I don't ever remember you saying that. <Heeee!> Or, maybe I misinterpreted you... I thought you have/had said (all three times I've went to this lecture) that ozone, among other benefits, improves skimming... hmm... Best, Sara M. <Does greatly improve, even to large extents at times, replace skimming... All are useful adjuncts to water quality improvement... Cheers! BobF>

Re: Algae, I am at my wits end, BGA contr., skimmer sel, O3 story   2/23/07 Thanks for the reply Mr. Fenner.  To answer some questions, I do have some Chaetomorpha algae in my sump, which does not seem to grow. <Good> I have a borderline DSB, some spots being quite deep 4" or more and some being less. <Mmm, I'd add to...>   I am a little reluctant to put more PhosBan in my tank because it lowers alkalinity although I personally do not believe that phosphates are my problem. <I agree> I have re-read the article you wrote and all makes perfect sense, the only thing I can come up with is perhaps buying a new skimmer that is more suited for a tank my size and better collection of DOC's. <Might help> Speaking of protein skimmers I recently got a mouthful of skimmate <Blechhh! Been there, spat that!> because my skimmer (Aqua C HOB) is in my sump and I don't have enough clearance to remove the collection cup, so in between cleanings I siphon the skimmate, not good.  I was wondering what your thoughts were between the Euroreef RS-135 vs. Aqua C EV-180, either one would be better suited for my tank. <Both are mighty fine units... I like the AquaC marginally more here> In your article you also pointed out that use of ozone for better skimming is also useful and the EV-180 comes with a ozonizer hookup, which would be useful if needed. <Yes> Please, please, please explain to me the use of ozone (I have read the article many times and its not clicking in my head) and the reasons for not wanting it to escape into your tank, and for that matter how you keep it from entering your tank (assuming you don't have a skimmer with a ozone hookup).  Thank you very much, Ryan. <Mmm, the short of it/this is the Ozone (actually a triatomic molecule of Oxygen) readily "falls apart" to form a much more stable diatomic molecule (the twenty and a bit percent of that stuff between you and the screen)... the unstable monatomic Oxygen atom really wanting to combine with whatever it can find greatly expedites the removal of organic molecules... in your skimmer. BobF>

Ozone questions 8/9/05 Hello WWM Team! You have answered some of my previous questions professionally and in tremendous detail, so I am back with another. The question isn't particularly about my system so I will save time with the complete set-up run down. The question stems from an outbreak of Cyanobacteria in my 250 gallon reef tank.. <Thanks for the kind words!> I do run an 100mg Ozonizer. It is coupled with an AquaMedic Turboflotor 5000 and controlled by an AquaMedic RedOx controller. The venturi can freely pull ozone through the generator which it does. Without the ozonizer switched off the tank would normally sit around the 360mv level. On it will usually be around 380-400mv. On and off I'm talking weeks not hours by the way. <All sounds good.. Kudos on the controller!  This is a must in my opinion and some folks try to skimp and not use one.> Taking me a while to get to the actual question here...sorry. Why does the skimmer produce very little skimmate and of a watery nature when the ozonizer is on But produces coffee coloured skimmate when off? The foam height in the reactor does not change, just becomes clearer and the skimmate is less, yellowy and watery. Why is this? <Ozone actually oxidizes the organics, reducing their molecular size as well as making them less "colorful".  See Reef Chemistry Expert Randy Holmes Farley's take here: http://web.archive.org/web/20030415033358/ http:/home.mweb.co.za/jv/jv79/reef/skimmers2.html I am concerned about this. If the skimmer produces lots of brown stuff when the ozonizer is off where is it going when it's on?.  I have seen numerous posts regarding this but not a real indication as to what is actually happening. If the ozonizer is cracking these organics and the skimmer isn't collecting them where are they going?. <It is being broken down by oxidation.  The consequences of this are hard to pin down.> I am trying to rid the system of these organics to reduce the amount of Cyanobacteria in the tank in turn, I am getting confused as to whether I should stop with the ozone, decrease etc. Please help. Best regards. Lee <It is hard to say what will give the greatest benefit toward reducing the Cyano.  I would suggest running the ozone for a while and observing the Cyano.  Stop the ozone and again observe the Cyano.  This will help you determine which is better.  All that said, I suspect that stronger water movement, higher pH and higher alkalinity and reduced phosphate (via water changes or chemical media) will produce greater benefits than manipulation of ozone.  Hope this helps.  Adam.>  

Ozone questions follow up 8/19/05 Hello there,  Thank you very much (Adam) for the prompt reply and for the Randy Holmes recommendation, good read. I will go with your recommendation, seems logical. I have been engrossed in the FAQ's and articles on skimmers and have decided that I really do need to somehow guide raw surface water to my skimmer (AquaMedic Turboflotor 5000) and place the skimmer feed pump into a stable pool. I am not doing it this way at the moment...wrist smack. I am convinced that in a tank of 250 gallons plus, with 140 kg of live rock, 14 fish 30 corals +, more skimmate should be produced. I would say I get a 'tea cup' full of watery brown liquid every 3 days at best. Not good enough in my books. The skimmer is clean, needle wheel clean, I just think I am not using it to it's maximum. Any other ideas?  <Feeding this skimmer with surface fed water will help some, but only really if it is not allowed to settle in any vessel first (see more below).  Other than that, I would just be sure that it is adjusted optimally.> I'm not going to ask if raw water will improve the skimming efficiency as it's answered in many areas on WWM....But I am interested to know how to set up the area for the skimmer feed pump. i.e. what is the best way to get that surface water once it has been dispensed from the drain....surely it mixes up and dilutes the oily proteins when it enters the sump? Teeing the water from the drain isn't an answer as the water flow is not stable enough. I've tried it and the water level in the skimmer is un-stable, possibly the Durso standpipes, air bubbles etc. rendering one of the reasons for this exercise pointless. I would prefer to feed from my pump (OR2500) anyway. I await your expert help. Many thanks, Lee <Actually, the proteins don't get diluted in the sump.  If you think about it, the entire sump is filled with surface skimmed water, so it should have a fairly consistent concentration of organics.  The real issue is that the sump has it's own air/water interface that attracts the proteins away from the skimmer feed pump, so getting the water before it has a chance to "separate" is the real trick.  As you have seen, it is very hard to feed a skimmer this way and maintain a stable water level.  This is why few aquarists do it.  Best Regards. AdamC.>

Are ozonizers a thing of the past? 10/8/05 Hello WWM crew!! This is basically a simple question. I would like to set up my tank again. It ran for 2 years, but because of Hurricane Francis & Jeannie last year ( I live in Florida and we lost power both times for about a week) I lost everything, except a tomato clown, a purple lobster and a few blue legged crabs which I took on to my Q tank and took it to my sister's. Anyway I have a 75 gallon tank with 40 lbs of what used to be live rock and I wanted to set it up again...  So I went to a LFS and asked questions about how can I improve my actual set up, and I came up with the question if I should replace the UV sterilizer for an Ozonizer for better results overall. And the salesman replied that Ozonizers are a thing of the past, that UV was the way to go.   I Didn't know much about the ozonizer until now that I have read a few articles posted here. I'm more inclined into getting one and start the hobby again, but I don't want to spend money for something that is out or will soon be..  I personally did not have a good experience with the UV Sterilizer and its many burnouts of the bulb, but again, maybe it was a bad UV Sterilizer (Sealife Systems double helix 9w ). The question is are UV Sterilizers the way to go today and Ozonizers a thing of the past?  <Ozonizers have been around for ages and will continue to be around. I don't see them becoming obsolete in the near future. Although neither is necessary to attain success in this hobby, both do provide benefits to the aquarium. As to my choice...being my tank is reef, and if I did want to employ one of the two, I would go with ozone.  The downside of UV is that it kills everything good or bad going through it. If the tank is and always will be a fish only tank, then I would go with a quality UV system. Ozone generators really need a controller to properly maintain ORP levels and they are rather expensive. James (Salty Dog)> 

Ozone Delivery - 04/06/06 Dear Bob, <<EricR here tonight.>>    After doing some research on how to improve the quality of water in my reef tank, I've come to the conclusion that introducing  ozone into the system is the way to go. <<A useful tool yes, I employ it myself...but is not a panacea.  I'm not trying to discourage you, just wanting to set realistic expectations.>> After reading the many FAQs on this subject, and how it is best to introduce ozone through the protein skimmer. <<There's no argument that many, many people (including myself) use this method of employment, but this may well 'not' be the best method for employing ozone to gain the most efficiency/safety.>> Here is the problem.  I have an AquaC Remora protein skimmer, the instructions say that this skimmer was not designed for use with ozone. <<Then best you don't.>> What my question is, does this mean I have to go with UV sterilization, or is there another effective way of introducing ozone into the system without using the skimmer??? <<Other methods?...indeed my friend.  Do a Google search for 'ozone reactor' on the Net...DIY plans about as well.>> Thanks, Angelo <<You're welcome, EricR>>

Huge ICH problem - control by Ozone? Mmm, nope  - 05/13/2006 Hi guys, <And some XX's...> This is the first time I have emailed you guys, as have spent ages reading the great amount of information on your site. What's stopped me? <Don't know> Well, I realize that you're busy, but this I couldn't keep to myself - it's distressing my fish (and killing them) and upsetting me, even the cat seems saddened by our misfortune. <Yes> I have a 240 litre reef with 40kg of live rock, MCE600, rowfos fluidizer, Eheim wet and dry, a UV filter and will soon be adding Ozone, monitored to the MCE600. The stock in the tank is as follows: 6 common clowns. 1 baby tang and a larger one. 4 shrimp (cleaner). Bristle star fish (I think that's what it's called!) Red Star fish. Snails and hermits. Recently I added a powder blue <Tang? This system is too small for an Acanthurus leucosternon> and didn't notice till I got back from a business trip, that it had Ich. <Yikes... no quarantine?> By the time I could get some treatment the next day it had died. Ich has now spread throughout the tank and we've lost 3 clowns already. I have tried one of the shelf treatment ' ESHA Oodinex  ' but the Ich is still there, but not as prevalent. <... your system is infested> I realize that my UV setup is working as well as it could and will soon have more flow running from the Eheim back to the tank, as previously it was working on a separate pump that works the Rowa-phos fluidizer. Will adding Ozone to the skimmer help in stopping Ich? <Nope> I appreciate your help. Many thanks in advance. Stu <Uhh... not so fast... Please read here: http://wetwebmedia.com/ichart2mar.htm and the linked files above... formulate a plan... and act... quickly... to eliminate this parasite from your system. Bob Fenner> Ozone Usage/Amounts...Iodine Supplementation - 08/30/06 Dear Bob, <<EricR here>> I have a 180g FOWLR.  1 large Emp angel, 1 large majestic, 1 Foxface, 1 Heniochus butterfly, 4 skunk cleaner shrimp. 2 perculas, 1 macaroon, 1 blue damsel, 1 goby, hermits and snails.  The system has been up for 1 year and doing fabulous.  I have 2 wet-dries and use bioballs for media.  2 sump located skimmers AquaC EV-180 and Euroreef RS 130, <<Good skimmers...some authors recommend using multiple skimmers of differing design to optimize the efficiencies re>> One UV 55-watt Aqua UV.  10% water change weekly.  I have started using ozone injected thru the JG fitting of the AquaC and the results are visible: crystal clear water. <<Indeed!  I find ozone to be more efficient than carbon is this respect>> I note that AquaC recommends 50-100 mg/hr of ozone but not more since skimmate production deceases with higher amounts. <<Mmm, yes...and I have read some debate on whether this is desirable or not.  Some speculate breaking down the organic molecules with ozone makes the skimmer less efficient...some speculate breaking down the molecules make the organics more readily available to assimilation by the corals...some say "what the heck", the skimmer is still as "efficient" as it ever was (just has less to skim), the corals "may" be finding more food (just be aware nuisance alga too will have more fuel), so if nothing is being malaffected what is the concern?  I tend to fall in to the latter category I have a Red Sea 200mg/hr ozonizer with integrated controller.  Tank ORP is 315-320mV during the day and rises to 340mV just before the lights go on in the AM. <<Sounds about "ideal" to me>> I have been using 175 mg/hr of ozone in this tank.  At this level the amount of skimmate has gone down from both skimmers. <<I have experienced this phenomenon as well>> The ECV-180 has 275 gal/hr flow rate and the Euroreef system has 180 gal/hr rate. Would you recommend that I go to AquaC's recommended 50 mg/hr? <<Based on your ORP readings and the fact you don't mention any deleterious happenings re, no, I would not drop the production rate that low>> Is it absolutely necessary that the skimmer effluent be carbon filtered? <<No...the amount/concentration of ozone produced by these hobbyists units is easily burned-up in/blown-off by the skimmer>> Would using higher doses of ozone oxidize Iodine or other elements to the point of detriment where HLLE may be a concern? <<Addition of Iodine with water changes is recommended...else test/dose as needed>> Thanks, Have a nice day. <<Same to you my friend>> Jimmy <<Regards, EricR>>

Which type of Ozone producer? <Anthony Calfo in your service while Bob travels to Australia intent on speaking the language... which means, I think, that he will be shirtless with a hat on his head and a beer in his hands at all times <wink! to my friends in Oz>> I appreciate your input on the protein skimmer, it was on my list of things to upgrade.  <a must have piece of equipment> Are you telling me that an ozonizer is not a worthwhile investment?  <I personally find them to be a very fun toy after you've bought everything else. Really must have only in commercial applications if you have good husbandry at home (QT all new livestock)> And I have read all the FAQ's and not one compares corona to UV. Can you give me any ideas, I would greatly appreciate it. Thanks Don <they are two entirely different beasts with Ozone being far more useful and dangerous. Neither are necessary for a traditional marine aquarium if you QT (again). UV simply irradiates the water and denatures algae and some pathogens (if the flow if slow enough, the water is clear and prefiltered, the bulb is changed every six months, the sleeve is cleaned quarterly or more often... very strict to apply UV successfully). Ozone, besides being more effectively germicidal, also increases O2 and RedOx in water, naturally clarifies (better than carbon), makes protein skimmers work far more effectively and has little maintenance issues to name a few. Misapplied though it can kill livestock and make you ill. Determine your needs before plunging into UV or Ozone. Kindly, Anthony Calfo>

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>

Ozone or UV In a large main display (fish only with LR) like 360-400 gallons. What would be a better choice to add first for parasite/pathogen control. An ozonizer (500mg/l) with ORP controller, or a large UV (120 watts). We plan on following religious quarantining, but it is possible for crypto or others to occasionally get through dips/quarantine/etc. Don't want to envision trying to track/capture a tang in such a large tank. I know the UV will have to be de-sized from manufacturer claims, but am inquiring into effectiveness of each method. Thanks, Jim <The best defense against disease is first off a strict quarantine protocol. And then next, maintaining an optimum environment (water quality, foods/feeding, decorations/hiding spots, temperature, compatible tankmates, etc.). Now to your question, I would get the ozonizer/controller and skip the UV. Much more effective at killing parasites and helps to maintain top notch water quality when properly installed and monitored. -Steven Pro>

Don't Get Down From The Brown! (Algae)... Hi crew, 2 unrelated questions if you would be so kind: 1: Is there any evidence suggesting that use of ozone could contribute to fin degeneration  and/or HLLE? <I have not heard of any connection between ozone and HLLE.. More of an environmental "disease". As far as fin degeneration- it's possible that over-dosing ozone can damage tissues on the fish, and lead to other potential health problems. If used correctly, however, ozone is a very useful tool for enhancing water quality><<Indirectly does/would help... with improvement in water quality... RMF>> 2. I am in the process of breaking in a 20low which I intend to use primarily as a live rock/gorgonian invertebrate system, with a couple of hard corals; inhabitants will be limited to those collected in two to four feet of water in the Florida Keys. For this purpose, I am lighting with 130watts of power compact, 50/50 10,000k/actinic. The system is less than a week old, and I have moved several gorgonians and some Halimeda and Caulerpa from the tank it is replacing into it. The old system had a little brown algae here and there, but within a few days of being under the PC's it has really taken off, mantling the gorgonians, Halimeda and now the substrate; the usual algae eaters are present and doing their job, but not keeping up. <Algal blooms are common in new systems with abundant nutrients. And, when you add into the equation a lot of light-wham! A recipe for nuisance algae! The key here is balance...You need to activate nutrient export processes, such as protein skimming, water changes, use of chemical filtration media, and good overall husbandry techniques>     To date, I have fed very little, and plan to keep ahead of things with water changes until cycling is complete, but this algae is a problem; this is my first experience with PC's, and I assumed the high light levels would ultimately disfavor the browns. Any  suggestions would be appreciated. <As above, fostering nutrient export processes will really help, as will a dose of patience! In time, and with good water conditions, these nuisance algae will give way to corallines...hang in there!> Along the same lines, assuming use of turbo/Astrea snails, emerald crabs, and blue legged hermits, I would be grateful for an unbiased estimate of how many of each this system should utilize. Thanks for your help, Steve. <Well, it's really hard to say...I'd go for about 6-8 of each...These guys are good with hair algae, but may have minimal impact on the brown "slime" algae...Just keep maintaining good water conditions, and hang in there...These nasty algae will eventually go away! Good luck! Regards, Scott F>

Ozone generators Dear Bob & crew, Trying to get a straight answer. Does ozone injected into a skimmer specifically help remove phosphates and nitrates? I see in your FAQ responses that ozone helps remove dissolved organic compounds, but I¹d like to know about these two (end results¹ of the bio process specifically. <Does help to reduce these compounds> Also, I purchased a Euro Reef skimmer on your recommendation. Works great as advertised. Any recommendation on what Ozone generator or use on a Euro Reef CS12-2 and on a 400 gallon tank with heavy bio load? <Am still a big fan of the Sander's line> Except in certain circumstances, I know you guys shy away from product endorsements, but if you¹ve had any experience with a specific model of Ozone Generator on Euro Reef skimmers, I¹d appreciate learning from your knowledge. I really can¹t afford to buy two Ozone generators (the one I always buy first) then the best one for my situation (which I inevitably buy 3 months later when the first is yielding mediocre results). As always, best regards and thanks for your help. <Bob Fenner>

Lost in The N-Ozone Layer.. >Hi, I am completely lost on this. >>A map is needed. >What is ozone? >>O3, an unstable molecule of three atoms of oxygen.  It "wants" to get rid of one of those atoms, making it an excellent oxidizer, and killer of fauna micro. >How do you use it? >>Personally, I like the smell, so I sniff it.  I hear you're not supposed to, though.  J/K  One uses an ozone generator, and small amounts are fed into the water, often the water column of a foam fractionator.   >Is it expensive? >>It can be, I've never had call to use it, and haven't priced any units in years.  A quick Googlization should net many results. >I have read somewhere on WetWebMedia that it can be effective to control diseases like ich and other things. Thanks, Adam >>It can be, yes.  It's also used (more often I believe) to keep the oxygen saturation up, and maintain proper RedOx.  These are all things that are not, in my opinion, really necessary if you've properly set up a stable system, though.  If you're having trouble with disease, it's wiser to assess your husbandry.  Marina

Ozone questions 12/30/03 hey guys- <Hi Justin!>      i have a few questions about ozone. pretty much all i know about it is that you have deemed it beneficial. <Ozone does indeed have many benefits when applied appropriately.  IMO, Ozone has a place in treating specific problems, but is probably unnecessary for full time use in a properly maintained reef tank.> after sorting through your articles and faq's, i am still a bit confused. more specifically, how would i hook this up to my p.s. (AquaC ev-180 w/out ozone modifications offered by aqua-c) or is it even possible? <Jason at Aqua-C is outstanding with customer assistance.  He will be able to guide you well with this question.  You could also Jury rig a way to "T" the ozone into the air intake of the skimmer (being careful not to limit the air intake)>. 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), <It depends on the controller.  IMO, an ORP meter or controller is mandatory for use with ozone to prevent dangerous overdose.  Some ozonizers require an air pump to push air through the unit.> sufficient for my 80 gallon reef and an all around decent set of equipment? <This is probably more than enough capacity for your tank.  I don't know about the quality of this unit, but Red Sea almost certainly buys these units from some one else and re-packages them.> and about ozone, what specifically are the benefits, dangers, optimum levels, and how they are obtained? <Ozone oxidizes wastes in the water (as well as parasites).  Overdosing can be dangerous (literally burning animals), and ozonated water must be passed through carbon to remove any remaining free ozone.  Breathing ozone can be dangerous to your health, and allowing ozone to escape into your home must be prevented.  Optimum levels depend on the application.  If you are treating parasitic infections, very high levels may be desirable.  If you are just trying to help keep your reef tank water nice and clear, much less will be required. If you monitor RedOx (ORP) to guide your ozone application (most common and appropriate way), a "normal value is 300-350mV.  A typical ozonated reef tank should not be allowed to go much above 375mV.  If you are treating parasitic infections in quarantine, a value of up to 400 may be appropriate.> 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 Barstow <glad you have benefited!  Adam>

ORP level for controlling Ick?  5/103 Wet Web Media Crew Hello, I have a reef tank 500 Liters, and I'm using Aquazone 100 mg With ORP Controller, What I would like to know - How high should the ORP level be if I would like to Kill \ Weaken the ICK? thanks in advance,    Asaf. <there is no direct/correlative reading of ORP for controlling parasites. Disease control begins with proper quarantine of all new livestock in a separate vessel for 4 weeks prior to entry in the main display. That said... a good RedOx value with ozone in the aquarium is around 400mv (350-425mv range). Stability is better than occasional spikes to unrealistic highs (some folks push ORP to 450mv or higher). Best regards, Anthony

OZONE QUESTIONS-and a little help from the past FAQ's Hi Scott, I have one more... What exactly is ORP? <Oxidative Reduction Potential> I understand that skimmer increases ORP, which is good. But why certain people employ ozonators to increase ORP? Isn't skimmer good enough?<Do read below> Can ozone be dosed directly into tank, or does it need some kind of special chamber? Is it better than UV light at fighting pathogens?<Inject ozone through a proper reactor or skimmer and pass all effluent water over activated carbon, and change the carbon regularly---UV is used germicidally to reduce the numbers of pathogens (but no guaranteed cure, mind you). It is simple and safe but requires very regular maintenance to be effective... needs prefiltered and clear water clarity from chemical filtration regularly), bulbs need to be changed every 6 months (they are dear in price) and the reaction chamber needs to be cleaned/flushed at least monthly. Ozone on the other hand has numerous benefits: germicidal, adjustable, imparts oxygen to water, improves clarity (clears discolorants to reveal icy blue water, improve RedOx potential of the water (indirectly inhibiting algae) and more. However, it can be overdosed if not controlled. Must be used with a controller or at least watched with a RedOx meter. Effluent water must be passed over carbon changed regularly. With extreme misuse can be a slight to moderate health hazard to people. If you are moving fish in and out frequently, or if your system has a heavy bio-load, I'd suggest an electronic (not corona discharge) ozonizer with a RedOx controller and carbon chamber. If you are a casual aquarist with a central system that will not see frequent new entries (w/o quarantine)... then a UV may be safer and satisfactory.(Found this on the WWM...by Anthony Calfo :)> Thank you, Luke

Benefits of ozone Thanks again for some valuable information, <Welcome> After reading Bob's advice on the use of ozone I decided to buy an ozonizer and I cannot believe the difference in my tank!!!!! I had a suspected outbreak of Cryptocaryon and the ozone appears to have cleared this up and on top of this the water is now crystal clear with a significant reduction in nuisance algae. <All related benefits> Another benefit is that after adding the ozonizer I now have a newly acquired copepod population!!! thanks once again for excellent advice Frank from Glasgow <Welcome. Bob Fenner> Ozone on a Remora Pro Good Morning Crew! <Good Afternoon, Andy>       I just want to start out by saying Thanks for all the info you've given me; I've had a Marine tank for about 7 years now, and if I would have found this website things would have gone A LOT more smoothly in the beginning! I also want to take a second, and tell you even after all this time, I still learned a million things while reading The CMA, and I'm in the middle of Reef Inverts; great work, It's amazing how much information is in these books! <Thank you for your kind words.>       On to the actual question, though... I'm going to be moving my aquarium to a different room in the home (Actually, starting a new one, and tearing the old one down slowly), and after much research here, and on other sites, I've decided to try using O3 on the Aquarium with an ORP/Controller unit, still unsure on the brand, but positive it'll make a nice addition to the tank. I have e-mailed Aqua-C directly a few months ago, and was told that they don't recommend running Ozone with the Remora Pro, but stumbling through your FAQ's, I see that the crew has given people some instructions on how to do it. I've got some questions on the logistics of it, if you can help.       1. The skimmer has a Mag-3 pump, and I understand that most recommendations are to effectively "T" in an ozone line between the pump, and skimmer inlet. Are there commercially available T's, even with modification, that you know of? Or would it be better to feed the ozone at the pump Inlet? I can fab something up there...       2. The addition of "air" to the pump will produce a drop in flow; is there a way to calculate the drop, and up-size the pump accordingly? The skimmer works VERY well, I don't want to slow that down.       3. Can carbon be placed in the Pre-filter/skimmer box to filter the return water? And is it safe to have it dump into the main tank like this? I can place this in my sump if necessary, it's just a tight fit.       4. Is this thing even "Ozone Compatible", or would it just be easier to just buy a cheap, venturi skimmer not to skim, but to ozonate? If so, do you have any recommendations?       5. Or is there a better way to do this, like putting a JG fitting in the body of the skimmer?       Just some thoughts; I figured I'd ask this time, instead of doing things "My Way" and ending up with another box full of stupid equipment modifications and purchases (Anyone want a Sea-Clone 100, or a Nitrate Reductor? :)  ). Sorry for my verbose question; I've been rolling this one around in my head for a while now... :) <Andy, before I answer your questions, please reconsider using ozone.  It isn't a bad thing to do, it's just that if a tank is properly maintained, ORP levels of 300+ can be maintained without the use of it.  I only say this because of the cost of an O3 generator and controller is kind of pricey and I can think of much better things to spend money on than an ozone system.  If that is what you want to do, I'll go through this with you.  James (Salty Dog)> Thanks very much for your help- <You're welcome.> <<RMF disagrees>>             -Andy Broczkowski

Protein Skimming, Ozone, and UV Use in Marine Filtration 7/5/05 Hello Bob, I enjoyed your article on ozonizers on www.about.com. <Actually on WWM... a link on about.com> I have a quick question for you and don't want to take too much of your time but I would appreciate your opinion. I have a 240 gallon reef with a large population of SPS and LPS corals. With the introduction of ozone to have my protein skimmer at its peak efficiency would be great. But would the introduction of ozone into the contact chamber of the skimmer kill even the beneficial microbes along with zapping bacteria, microbes and unwanted organics? <Oxidizes all indiscriminately. What most folks shoot for is "enough" O3 to reduce free-living bacteria (most ones you want are not suspended in water) and organics...> You stated in the section where you discussed the cons of using a UV Sterilizer that one of the cons of using a UV sterilizer is that you also zap beneficial microbes as well as bad. <Yes... to some extent> In a reef aquarium my corals rely on a lot of the plankton and microbes for food. Would the ozone affect this and is there any recommendations you can suggest on the usage of ozone? I look forward to your advice. Thank you, John Vu <In practical application John, folks have little lingering ozone... providing a few hundred milligrams per hour, delivered to/through your skimmer directly or not, will not harm your livestock. Bob Fenner>

Another Ozonizer Question - 07/23/05 My name is Bob, and this is regarding a 12 year old reef. <<Howdy Bob!>> I have done a lot of water changes over this time, and think I am burning out.... Judging from my degrading water quality. <<Um...ok(!?)>> Bob Fenner has sang the praises of Ozone for quite some time <<Many, including myself, feel he knows what he's talking about.>>, but EVERY one of my LFS are against it for the usual reasons (wipe out potential, "over clean" water. etc.. etc..)  My 3 quick questions are: <<"Over clean water?!"...excuse me while I have a chuckle...>> 1. I still plan on performing typical maint. practices, but is relying on ozone to "pick up some of the slack" improper thinking? <<Yes...ozone is an adjunct to proper maintenance/husbandry...not a replacement.>> 2. I don't plan on jacking the ORP up to the max safe limit, but to just the level needed to maintain crystal clear water (and whatever the ORP is...it is.) <<An ORP of/around 350 is a safe and useful level.>> 3. I don't read much about the long term maintenance of an Ozone system. I'm considering the Red Sea w/built in controller. <<Have read/heard good things about these...better units to be had for sure (Ozotech)...but the Red Sea units reportedly provide good service for value.>> What should I expect in terms of calibration, probe cleaning and replacement, replacement of the O/3 output device, etc.. etc.. <<Will depend on your system, amount of use, etc.... Follow the manufacturers recommendations.>> Thanks for all your help, and I suggest readers follow the link to make a donation to this wonderful site! <<Thank you for this.>> Bob <<Regards, Eric R.>>

Re- Another Ozonizer Question - 07/24/05 By " over clean" I'm referring to the elimination of micro-life, beneficial bacteria....etc.. etc.. <<Not a concern if/when applied responsibly/correctly.>> Thanks for the reply, I ordered the Red Sea...and promise not to rely on it too much! <<Excellent to hear.>> Bob

Ozone Concerns - 12/10/05 Hey Crew, <<Hello>> Happy holidays. <<Thanks...and to you and yours...>> I have a 180g FOWLR ~175 lbs LR with two large angels, Foxface, Heniochus, a damsel, three clowns, snails approx 30, hermits approximately 40. Water is absolutely crystal clear. <<Ok>> Tank is doing GREAT. I do use ozone <<So do I...>> injected with a dedicated pump through a Turboflotor-Multi. In order to keep the ORP at 330-340 mV I am injecting 175 mg/hr through and Aquazone ozonizer/controller. The ozonizer is on pretty much constantly. <<Ideally it would be, with the right setting on the controller...in my opinion.>> The ORP probe is in the tank and reads accurately. Water circulation is approx 10x per hour thru two wet-dries and another 1000 gal/hr circulation w/powerheads inside the tank. <<Very good>> Since I increased the circulation by adding the powerheads and cleaning my pumps to about double what it was a month ago my small Cyanobacteria problem has been cured. <<More/improved circulation is sometimes all it takes>> Is it acceptable that I use this much ozone to keep the ORP at this level? <<Sure...I have a large tank (375g) on which I run a very efficient 250 mg/hr ozone generator (Ozotech) wide open 24/7...through use of a controller of course. Since you're secure in the accuracy of the probe/controller you should be able to use as much as it takes. And since you are adding the ozone through your skimmer, any excess is being quickly blown off...though some folks feel safer by adding a small bag of carbon at the effluent output.>> Would it be better that I back off on the ozone production? <<I see no reason to here.>> I have tested the water immediately coming out of the skimmer before any carbon filtration and there is no detectable ozone even when the ozonizer is turned up this high. <<Yes...reacts/is blown off/utilized very quickly. The hobby units available really do pose little concern for residual ozone.>> I can smell the ozone under the cabinet. <<No more dangerous than an "air purifier" that uses ozone to clean the air. As long as you don't have residual ozone entering the tank (unlikely), it will be fine.>> I would like to keep the ozone going; over the past few months the most substantive changes in my system have been the addition of ozone and increased circulation. <<Both of great utility. Keep the ozone going...used responsibly as you are doing it will be of great benefit. The least of which as you have noted...water that is "absolutely crystal clear"...>> Thanks for the advice, Jimmy <<A pleasure Jimmy. Regards, EricR>>

Ozonizer I recently finished reading your book, ' The Conscientious Marine Aquarist'. I noticed you wrote; before buying any sort of meter, doser, denitrator, or UV sterilizer, one should first purchase an ozonizer. So without further delay I am wanting to purchase one. Although I have no clue of what type or size I would need for my 30 gallon reef. And is ozone something that can be harmful to one? Any information you can give is greatly appreciated. Thank, Rob. >> Ozonizers are indeed worthwhile additions to a filter strategy. Their size (milligrams of O3 per hour...) can be a little tricky depending on where you'll be introducing the triatomic oxygen... best to your skimmer... Look for the recommendations of the various manufacturers (mainly ESU and Sander's in the U.S.) units... they're labeled as such... and no to the danger question... Another largely urban myth... The amount and transiency of the ozone produced by these units precludes their being any real danger from their use... The use of aerosols and cooking indoors are far more of consequence. Bob Fenner

Ozone nay or ya Hi, My husband wants to add an ozonizer to are (already doing really well) set-up. I say leave well enough alone. Help us with this disagreement  please. Do we need one or not? Why?  P.S. The tank has been set up for two years now. sincerely, Georgia  >> Maybe not need, but an ozonizer is a great adjunct to enhancing water quality... increasing RedOx, dissolved oxygen, reducing overall microbe populations in your system, helping to keep the water clean/clear...I would get it way ahead of a ultraviolet sterilizer myself... Bob Fenner, who says yea

Ozone Bob, Am interested in your opinions on ozone generators. Are they useful or just another gizmo and do they reduce nitrates, phosphates etc at all. Cheers, Scott >> Very useful... IMO a better choice in more settings than ultraviolet sterilizers... For increasing D.O., RedOx, reducing DOC's (dissolved organic compounds)... eliminating color in the water, lowering TBC (total bacteria counts)... overall water quality improvement ... my further plug for this technology can be found here: Home Page  Bob Fenner

Re: ozone Bob, Thanks for the fast reply ,now a couple more queries. Is it right that the return water from the skimmer must go thru activated carbon before returning to the tank and if a small amount of ozonizer water should miss the carbon would it do any damage. Also would you run an ozonizer 24/7.I have a large tank-155g with a lot of live rock but it is fairly heavily stocked. I also have a U.V so would an ozonizer be overkill. Cheers, Scott. <Thank you for asking the "next questions" in logical order (part of the bane of these sorts of forums is the call for short, concise... unsatisfying pointed responses)... No to the urban myth of triatomic oxygen getting into your system, wreaking havoc... just doesn't happen with the small amounts of ozone the hobby's generators make... No damage from running yours 24/7 (this is what is done in public aquariums, wholesale holding facilities around the planet)... And a U.V. in addition is not overkill... complimentary in effects (reduces total bacteria, increases oxygen, lowers DOC...). Bob Fenner>

Ozone & Calcium Reactor Was wondering if either Ozone and/or Calcium Reactor would benefit a fish only system(150g) with live rock(160#) ? If so, should I use one or both during the curing of the rock or wait until cycled? Thanks, Lex >> Both would, do... and if I had them, I would definitely run both continuously... and during the curing period of the live rock... will actually speed and stabilize the curing process(es)... Bob Fenner

Ozone Can you tell me the benefits of an ozonizer... what it can do and what it  can't. I hear it will helps kill certain bacteria and viruses. Thanks >> Sure, in general terms. An ozonizer improves water quality by increasing dissolved oxygen content, raising RedOx potential, oxidizing dissolved organic compounds, reducing total bacteria count (don't know about viruses...), and bumping off algae... Just in passing will mention that there are western European countries which use ozone as their sanitizer, skipping (actually quite toxic) chlorine containing compounds...  Bob Fenner

Ozone and U.V hi bob, can ozone and U.V operated at the same time?  <Yes... in fact, some "ozonizers" are ultraviolet sterilizers...> my ozone is controlled by AquaMedic mv computer and I set to 350mv how much mg /h of ozone do I need to set i.e.: 10mg, 20mg or 40mg mine is a sander 100. <Hmm, if your ozonizer is controlled by a mv probe tie-in (ozone is/can be measured indirectly by conductivity), you shouldn't need to "set" your Sander's producer... If it were my system (you don't state what size, much else... I would leave a "100" on full blast and check the microSiemens per centimeter readings a few times per day, night... I doubt (if this tank is of size, has much life in it) that you will get into trouble with this unit, setting> my U.V is HW 2000 and how long do I need to on per day? which of this will kill parasite and will it kill crypt and Oodinium? lastly I heard for my pal in USA that there was a ban on king angel is it true? thanks <Leave the UV on continuously. Neither will absolutely (one hundred percent) kill all crypt and Oodinium... but both will help to improve water quality and reduce the chances of problems with infectious and parasitic disease. Bob Fenner. Oh, and the ban on King Angelfish, Pomacanthus zonipectus is over... Mexico "reopened" last year to collecting, and this fish is coming out steadily from Baja.>

Ozone Hi Bob! I would like to know more about adding ozone to my tank. I have had poor luck trying to find out information on this. I have so many questions about it. I am assuming it will increase the oxygen in the tank? <Correct... and raise the RedOx potential...> Does it really help clean the water as much as some say? <A qualified yes> Does it kill off algae and parasites? (floating) <Helps> How much is needed? <Depends on a few factors... size of tank, bioload, dissolved organics, desires on your part... a few hundred milligrams per hour likely...> How long should it be on per day? <Continuously> Should it be placed in the sump? <Better than a main system inlet, yes> What about the dryers? <Very worthwhile in humid environments... improves production of ozone considerably> What should I look for in buying a good unit ozonizer with controller and probe? <Hmmm, more than anything? The reputation of the gear with folks who actually have used/are using it> I am running a 55 fish only (shrimps, crabs and star fish too)(Live rock but no corals). Of course it is fully stocked but not too much so. I just want to clean the water as much as possible for my little friends. I hear that when ozone is added the protein skimmer sucks out even more gunk.  <Mmm, yes, and a good deal of the same sorts of materials are "burned up".> I have never had a problem in all the years of running saltwater tanks but anything that may aid in keeping the water quality higher for longer should be used. Tons of questions, very little answers so far. Help! Brad Zimmerman <Be chatting, my curious friend. Bob Fenner>

FO set up question... Hi Bob, I have a 100 gal fish only system with about 80-90 pounds of live rock. My setup also has a Turboflotor 1000 skimmer. I'm also Inj. ozone, plus two 25 watt UV sterilizer. My livestock consists of a lg queen angel, lg panther grouper, flame hawk fish, sm. Huma trigger, and a juv. Atlantic tang. The water is PRISTINE clear. Like I've never seen before while in this hobby for over 5 years. I believe its due to the UV sterilizer and electronic ozone gen. <Likely so... along with your excellent maintenance> Ok now for my question. Since I am inj. ozone to the skimmer. should I be monitoring the ORP???? <Hmm, if you're concerned about over-treatment... but this is likely not an issue... as it has not been> I figure inj 10mg/hr of ozone per 25 gallons. Is this correct??  <About right, safe> My fish are doing fine at this moment. It also seems that my skimmer works better inj. ozone. The collection cup has darker, thicker, dryer fluid in it when inj. ozone. <Yes, this is so... they work together better than alone> My last question is I keep my salinity at 1.018, is this ok? Because I also want to help manage , and prevent any disease such as ich. Thanks bob. <Yes for your FO system, this mix of organisms... and you're welcome. Bob Fenner> Lee

Protein Skimmer Hi, Bob. Checking out your web has become one of the things that I need to do everyday. Keep learning something new and keep having new questions everyday. I think that's why we get addicted to this hobby. We would never get bored! <Agree with you all the way around> Anyway, thanks again wholeheartedly for your contribution to this hobby. Now my questions are: Before I connected the protein skimmer with an ozonizer, the protein skimmer had collected brown colour waste. Now after I added the ozonizer, the protein skimmer could only extract clear water. The tank water is actually a lot more clear than before. Should I be worried about that? <No, this is to be expected> I told u last time that I have been having difficulty in keeping tomato clown. You suggested me that I can try some tank-breed small ones. Unfortunately, the LFS here only offer the wild ones. I am thinking to add some bubble tip anemones in the hope that it will help the tomato acclimatize. Do you think it helps? please note that I have no experience at all in keeping anemones. <Skip the anemone... hard to keep for now. And order the Clown/s from an etailer. A few are listed on the WWM links page. Amazing that a LFS would not offer tank bred species here> Thank you very much in advance. Eric <Be chatting my friend. Bob Fenner> Eric Ho

Coral Life model 50 ozonizer Hi Bob, In my aquarium inventory. I've stocked quite a bit of aquarium equip. Over the years while being in this wonderful hobby. I always keep my stuff, never selling them. Anyhow I have a Coral Life model 50 ozone gen. It puts out 50 mg of ozone. The package says up to 130 gallons. Yeah if your wondering I even keep all of the packages. <Good idea... so do I.> Ok my tank is now a 240 FO system. even though this unit is for a 130 gal. tank. Will this unit benefit at ALL if I tap it in with my Turboflotor skimmer on my 240, even though its undersized? Will a little bit of ozone present make ANY diff??? Thanks again. <Yes... it would be beneficial to apply 50 milligrams of ozone every hour to your system. As you state, perhaps less than optimal, but of use nonetheless. Bob Fenner> Lee

Ozone question? I hope I am no pest.  <Anthony Calfo in your service> Please explain why or why not to use ozone for my central filtration system. U.V sterilizer will help? <UV is used germicidally to reduce the numbers of pathogens (but no guaranteed cure, mind you). It is simple and safe but requires very regular maintenance to be effective... needs prefiltered and clear water clarity from chemical filtration regularly), bulbs need to be changed every 6 months (they are dear in price) and the reaction chamber needs to be cleaned/flushed at least monthly. Ozone on the other hand has numerous benefits: germicidal, adjustable, imparts oxygen to water, improves clarity (clears discolorants to reveal icy blue water, improve RedOx potential of the water (indirectly inhibiting algae) and more. However, it can be overdosed if not controlled. Must be used with a controller or at least watched with a RedOx meter. Effluent water must be passed over carbon changed regularly. With extreme misuse can be a slight to moderate health hazard to people. If you are moving fish in and out frequently, or if your system has a heavy bio-load, I'd suggest an electronic (not corona discharge) ozonizer with a RedOx controller and carbon chamber. If you are a casual aquarist with a central system that will not see frequent new entries (w/o quarantine)... then a UV may be safer and satisfactory. Kindly, Anthony>

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