ORP
Hi!
<Hello>
I have another technical question for you. I have a Neptune controller. When you go to the ORP setting it has an option to turn on the pH compensation or to turn it off. When it is on my tank gives a reading for 430. When it is off the tank reads 370. Which is the correct reading and what is the point of having the compensation option?
<Correct reading? Mmm, they're both "correct" as in accurate for the probe/gears sensitivity/reading as a function of pH... In other words your "tester" gives different readings at different pH's... Which are indeed a reflection/mirror of the ORP at those pH's>
As always you have been most helpful. Right now I have a fifteen hundred gallon system in Fairbanks Alaska and I would never have been able to do it all without your advise at every step of the way.
<Glad we could "go back and forth". No worries re the Redox readings here. Bob Fenner>
Thanks...
Bhaskar.

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

Ozone
Hi there
Fascinating reading your FAQ pages on ozone in aquaria.
One question. In setting up a system to benefit from residual ozone in the actual fish holding tanks as well as for water treatment - where would you suggest the ORP controller be placed in the water stream and how would one choose a site for a second ORP monitor in the 'fishy' tank? Andy Campbell
<I would never recommend stray or residual ozone in the main display... a very precarious and difficult to monitor application. Inject ozone through a proper reactor or skimmer and pass all effluent water over activated carbon (changed regularly). If using two probes, I'd take at least one reading from the surface near the overflow. Kindly, Anthony Calfo WWM crew>

Ozone question
I saw awhile back you answered a question on ozone. Anyhow, I have a wet/dry system with a built in skimmer (CPR). I'm considering plumbing a small ozonizer into the skimmer (Red sea with ORP probe). Anyhow, since the probe controls how much ozone gets by, where is the best place to put the probe to control ozone amount ? 
<At a point distal to the discharge of the skimmer... ideally, into a sump area where a non-hang on fractionator is deployed>
Does it have to be before the actual wet/dry BioBale since you don't want too much ozone going into your bio-filters - won't it kill that bacteria ? 
<Enough ozone will kill bacteria, all life>
So I guess you lay a bag of carbon on the overflow to the BioBale, and put the ORP meter between the carbon and the BioBale and measure there ?
<Yes, this is the best spot>
Kind of lost here on trying to determine where to measure the ozone and not kill my biofilter. Thanks
Jim
<I understand. The ozonizer addition is still worthwhile. Bob Fenner>

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

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

Strange bubbles (Ozonizer)
Very strange. I hooked up an ozonizer into my skimmer. ORP point is set at 300 coming out of the skimmer into the sump. Anyhow, I've noticed that some strange bubbles have formed at the top of some rocks. These bubbles are kind of shiny and about 2-3mm in size. Look kind of like mercury drops on top of the rocks. Not very many of them, just on top of one or two of the rocks. is this caused by the ozonizer working, and what is it ? 
<Likely either simply "cleaner" water or clearer water. Yes, because of the ozonizer... and slime molds, algae, etc. producing more oxygen, it getting trapped twixt them and the rock substrate>
I can shake them loose with a feeding stick, but they come back the next day. . .. Very strange, as it just doesn't look like a natural water bubble. . .
Thanks
Jim
<Nothing to worry about. Bob Fenner>

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
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

REDOX, O3, & U.V.
Bob, 
I was curious if you could point me in the direction of a source regarding the output of O3 from a U.V. sterilizer in closed systems? I know the amounts would be trace but I'm curious as to its over all effect on REDOX and dissolved oxygen. 
<Wish I did have a ready source or lead here. Both Redox and D.O. are improved by U.V. ozone generation... and the amounts of O3 produced by some U.V. units are appreciable. I would contact the actual manufacturers of the units (a few links on the WetWebMedia.com Marine Links, General Links pages) and ask them in turn if they could provide you with references. Alternatively you might run on over to a large college library, ask someone to help show you how to do a computer search (in the science, technology library/section) as: http://www.wetwebmedia.com/litsrchart.htm
Lastly, you might well want to do your own experiments here... using different samples of water, times, turning the U.V. on/off, measuring the values you're interested in. Bob Fenner>

Ozonizer or UV sterilizer?
Hello again!
<Salute! Anthony Calfo in your service again>
This time I need your advice about the next step I should make in order to be more "conscientious" (I got Bob's book just yesterday - ordered it from Amazon.co.uk).
As you can suppose, I have neither an ozonizer nor a UV lamp.
<not necessary but sometimes quite helpful>
My marine aquarium is 210 liters (approx. 55 gallons) and is fish-only (for the time being!).
I have an Eheim external biological filter (not a wet-dry one) and an Eheim internal sponge filter (I replace the sponge with the Eheim activated carbon for two days a month - is it ok?) ,
<you certainly can treat with carbon for a longer period of time, even full-time for optimum water clarity>
a two-way internal protein skimmer 
<do adjust so that it can produce dark skimmate daily>
and an electrical circulator. I used to have an undergravel filter but I was told that it makes no sense to keep it since I have an external biological filter, so I took it out. Ammonia is 0.0, Nitrite is 0.0 and Nitrate is 100 mg/lit (maximum of the Tetra test kit!). My Blue Tang has already been through twice a fungus disease and once Amyloodinium. I am told that the installation of a device will help to avoid some of the diseases...
What will be my best choice to start with? I have been told that for a small system like mine the best is to get a UV-lamp. 
<definitely safer, although not a guarantee to prevent diseases. For that, a quarantine tank for all new fish or occasional sick fish would be better>
Some of them are fix - their lamps are not replaceable (I have been told). 
<if so please avoid these models>
Which one should I buy? Is the Tetra UV lamp reliable and good quality? 
<a good reputation/brand. Do be sure to buy a model with a quartz sleeve for easy to replace bulbs.>
Which size? 
<in American wattage, a 15-25 watt unit for your tank>
I really do not know. May be too many questions (sorry!)
<no worries at all, my friend. Anthony Calfo> 
Best regards, Thanassis (your Greek friend)

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

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!

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>

Ozone & U.V.
I told you I had a two part question but couldn't think of a great way to formulate it. I've read your book and perused WetWebMedia looking for an answer to a specific question about ozone. I want to start using it in small amounts in my Top Fathom TF300 skimmers. If any residual ozone is passed through a U.V. sterilizer will it be destroyed or converted back to standard oxygen?
<You can do experiment/s to ascertain this yourself... mainly it will pass through and be added to by the UV's action>
We are talking about the small amount generated by the tiny "Coral life" brand ozonizers set to low. No output level was stated in the destructions but I have noticed a major performance boost in the skimmers the few times I've used it. My concern is ozone getting into the main tanks and rotting the rubber O rings on my bulkheads? Ozone is an after thought so I never checked to ensure these gaskets were U.V. resistant.
<Ah, not a problem. Very little ozone involved, almost none that gets as far as the tank itself. Bob Fenner>

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>

Ozone Generators
I am currently deciding between two type of ozone generators available locally for my 1100lt reef tank. Preference would be an Red Seas Aquazone 200 plus with controller however I can't find them locally and trying to get one for the US via the net to Australian Electricity Specifications , 240 volt 50 cycles, is proving difficult.  Perhaps you could recommend a stock list or tell me the conversion where the output is expressed in liters per minute to mg per hour
<I would suggest that you contact Red Sea Pharmaceuticals directly and talk to customer service or technical support. They sell these units worldwide and can probably put you in touch with a local vendor carrying a unit for your electrical specifications. Try the contact information at this page, http://www.redseafish.com/> Thanks
<You are welcome, Steven Pro.>

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
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>

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>

Ozonizer
Bob,
I have a Red Sea ozonizer that I want to use but have not found any way to filter out the ozone. 
<To filter out the ozone?>
Tried pumping the out put of the reactor into a chemical chamber filled with carbon, but was still smelling the ozone. 
<Doubtful... these units produce very little... tens of milligrams... thousandths of grams of ozone per hour... Gets "used up" very quickly.>
I have heard that you can use a protein skimmer, but I can find no info on how to set this up. Any information would be appreciated.
<Please read through the ozone FAQs section of our site: http://wetwebmedia.com/ozonefaqs.htm
And associated links, peruse the Oz'Reef link re DIY possibilities... and otherwise don't worry about this unit or ozone "contamination". Bob Fenner>
Thanks,
Leldon

Activated carbon/ ozone
Bob,
Is it essential when running ozone, that the returning water from the skimmer be run under carbon???? This seems like a controversial subject. Thanks again. Lee
<Not essential in almost all cases... part of an ongoing "urban myth" in the hobby (along with the lack of necessity of thermal acclimation, floating livestock polyethylene bags... please stop me). There is so little O3 produced by corona discharge hobby units there is exceedingly small likelihood of ozone "poisoning" (and extremely tiny chance of "space poisoning" the area around the aquarium/s it's used in...). If curious, get/use a conductivity or Redox meter and measure the change in water quality in/about the use of this ozone-generating device. Bob Fenner>

Request from Belarus (seeking large ozonizer)
Dear Sirs,
I'm a private farmer from Belarus. I'm starting a sturgeon growing farm project. I'm currently installing 32 primary growing tanks, each with a capacity of 1000 cubic meters of water for initial fish development. I'm looking for an industrial electrolytic ozonizer with 2-3 kg/hours productivity. If you have one or know a company manufacturing electrolytic ozonizers, please, provide me with the information. I appreciate your help with this question.
<I would first contact the folks at Sanders in Germany, and Ozotech (http://www.ozotech.com/) in the U.S. for input on who in your area might have units already specified for your application. I will post your query on our site (WetWebMedia.com) in hopes that others have input for you. Bob Fenner>
Vasiliy Vergueychik
Private farmer
5 K.Marx St., office 27
Minsk 220050
Belarus
tel./fax: (375-17) 227-0442
e-mail: lsokol@home.by

Re: request from Belarus
Dear Mr. Fenner,
Thanks a lot for prompt reply and for your valuable information. We will contact the folks at Sanders in Germany. But I've head that the industrial electrolytic ozonizer are manufactured only in the USA. Is it true?
<Don't know. But am sure the folks at Sanders will know. Bob Fenner>
Best,
Vasiliy

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

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

Ozonizer
Mr. Fenner, I hope you had a great time on your trip. I recently got your e-mail and purchased a American marine ORP monitor/controller today hoping this would save me time experimenting with the degree of ozone in the water.
<Good move>
I know you do not like commenting on any brand make or model, but is this a decent monitor?
<Yes>
And should I still keep a close eye on the ph of the system?
<Hmm, not so much with the controller, no>
I bought it that way if the Redox got to high the monitor would shut it off. Hope to hear from you soon, but really not a rush enjoy your Sunday...Ryan H.
<On the way back from MACNA... in Detroit/Motor City... Bob Fenner>

Re: ozonizer/ph
Hello Mr. Fenner e-mailed you yesterday about a ozonizer I recently purchased. It was the one made for a spa that puts out 250mg/hr. I have a couple of questions. One is the rubber hose on the Rio pump connected to my CPR protein skimmer prone to corrode due to the ozonizer?
<Likely... see your dealer re ozone resistant tubing>
My second question is I have no controller or Redox monitor if I was to run the ozonizer for 4 hrs and the ph did not rise do you think it would be safe to run it 24/7?
<Hmm, I would continue your experiments for now... like eight hours a day, then twelve... and monitor at least pH... once your organics that can be, are oxidized, you may well experience a "jump" in pH... and more>
How would I go about testing how long to keep it on?
Thanks again Ryan H
<Chat with you soon my friend. Bob Fenner>

Ozonizer
Hello Mr. Fenner, I have a couple of questions regarding a ozonizer I purchased recently. My LFS sold me a Clearwater ozone system s-1200.It puts out 250mg/hr. I have a 55 gallon reef tank with a fox face, two cleaner gobies,1 mandarin, about a hundred anthelia polyps, fifty green polyps, seven mushrooms, seven sea mats, and a large zinnia's for filtration I have a thirty five gallon sump wet dry system with two chambers that I have carbon and poly filters. When I got the ozonizer home to my surprise It was for a spa!
<Hmm, yes, manufacturers do make "cross-over" sizes for both functions... 250mg is quite a bit for ninety gallons (your sump and tank)>
Which really threw me for a loop. I'm not sure if this was a wise decision? I hooked it up last night through my CPR in sump protein skimmer. This morning I found my o'ring broke and the collection cup fell in. So I put my spare on and when I got home it had broke also! Do you think this was a rare mishap?
<These are flimsy o-rings for sure... but the ozonizer probably is at play here... corroding the o-ring before it's time>
I'm pretty sure it was. I know you are a fan of the ozonizer so I'm giving it a try...Well before I stop chatting I just wanted to let you know your books are great. Your website without a doubt is the best around. Talk to you soon. Your friend in New Orleans...Ryan H
<Outstanding! Thank you for making my day. Do keep your eye on the pH of your system should the ozonizer prove to be too much... if you can "dial it down", I would... to about the 100 mg/h range... otherwise, do monitor Redox (reduction oxidation potential) if you can, or at least pH... and turn the unit down, or if need be, off, should the pH exceed about 8.4. Bob Fenner>

Ozonizer
Mr. Fenner, Thank you for the quick advice as always. Quick question what would you use to support the collection cup if the ozonizer is at play
Thanks again Ryan H.
<What we have done with our CPR hang ons is to build up a "lip" of silicone rubber (the 100% type... designated for aquariums or no... just not with mildewcides in it...) and let set up for a day or so... then squeeze the collection cup in through this permanent seal. The fine folks at CPR have looked into this issue as well... Bob Fenner>

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

Ozone
Hello Mr. Fenner,
I bought your book "Conscientious..." and noted your recommendation on an Ozonizer. I also have read the FAQ's concerning Ozone on the WetWebMedia site as well. I am in the process of setting up a 110g LR/LS/Invert w/ a Wet Dry and skimmer tank. My question is what "size" ozone unit would you recommend for my tank - 50, 100, or 200mg/hour?
<For how large a system, amount of livestock... about the same "size" as gallons of system as a rule of thumb. 50 mg/h for a fifty etc.>
And I noted you have recommended Sander's models in past posts, but I am partial to the Aquazone because of the built-in probe/reading capability. Would you consider this brand a good one?
<Yes, reliable, a good value.>
Lastly, I have read several concerns about UV's killing good bacteria along w/ bad...any such related concerns with an Ozonizer?
<Negligible>
Thank you so much for your time.
Keith.
<Thank you for asking. Bob Fenner>

Qzone
Hey Bob, can you please tell me if I can run my red sea ozonizer directly to my Turboflotor 1000 and how or do I need a pump and drier. I would be very thankful for any info you can give me on how to install correctly with this skimmer.
thank you, David
<Yes, you can install these units together as you suggest... and yes, a dryer would be beneficial depending on how dry the air is right around your ozone generator... you could measure ORP via a meter to determine just how much more useful... 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

Ozone
So I read up on ozone using your FAQs, articles and some info from buy.com
<Okay>
Confused to say the least. What brand do you recommend for my 100G fish only tank with the 55G sump? How much do these cost? I don't see this info on your FAQs.
<Not a big fan of such demonstrative statements... brands, makes and models change over shorter than you'd think time... Let's say for the record the Sander's lines... a couple of hundred milligrams per hour production... a couple of hundred dollars US>
The info I found at buy.com somewhat contradicts your other articles/FAQs regarding Activated Carbon because they say to place carbon after the ozone, before it returns to the main tank... but you state carbon becomes ineffective within a few short hours. So how do you "do both"... ozone continuously and carbon-filter the return water?
<Different purposes here... actually to absorb the "excess" ozone...>
One other point I couldn't really discern from your FAQs... can you over ozone a fish only tank or is over ozonizing primarily concerned with a reef tank full of inverts?
<Hmm, both... Time to invest in a "complete" printed work on aquarium set-up, maintenance... hard to understand any universe from simple question/answer statements... don't you agree? Bob Fenner>

No (apparent) results from our MORE-ZON 30 ozone generator
Dear Bob,
We are the Florida Ft. George Island people who wrote to you the other day totally frustrated with our hair algae episode. ONE of the things we're trying is an ozone generator. We purchased a "More-Zon 30" and hooked it up to the Venturi on our Sealife 150 protein skimmer hoping to instantly watch a frothing production of skimmate.
<Yes, typical>
What happened was that indeed the water in the column looked more foamy but would only rise a mere inch above the swirling water mix in the contact chamber. The water in the chamber looks pure- no discoloration.
<Hmm, can you adjust the water column in the skimmer's contact chamber... You want to remove the "frothy" part, whether it is a dark/er color or no>
I have tried for 70 hours to produce skimmate using my new ozone generator and have yet collected anything. The water swirls and bubbles only to midway in the contact chamber and never even rises to the collection cup. Previous to the installation, our protein skimmer put out at least 1 Tablespoon of coffee-colored skimmate per day. The odor released into room is pungent smelling. What are we doing wrong?
<Likely absolutely nothing... the O3, ozone is "burning" the darker material you used to collect "up"... Does this make sense to you? Sort of like burning a cigarette in an oxygen tent (of course, don't do this...)...>
Thanks for any help you can offer us. We are going to lick this hair algae thing one way or another, if I have to stick my head in the tank and graze on those rocks myself!!! Patti,
Thanks, Scott and Patti
<I know you will my friends... Do adjust the intake and/or discharge valves/water coming in/going out of the skimmer, elevating water height in the contact chamber, to remove some of the "dry" "white" foam... and try to be patient... in a few days to weeks you will see definite differences in your system. Bob Fenner>

Ozonizer Requirements and Recommendations
Bob;
I have a 90 gallon marine (non reef) tank that has been very lightly loaded for 2+ years (4 medium sized fish). I plan on increasing the number of inhabitants by 6 or 7 for a total of 10 or 11 fish over the next 2 months. The tank is very stable and water quality appears to be good with this light load. I currently have an Amiracle SL150 Wet Dry, a Fluval 304 Biological Filter and a 15 or 25 Watt Emperor Aquatics UV. I drive the Wet/Dry with a Quiet One.
<Okay>
I plan on adding a Berlin Turbo Skimmer and since I already have an ORP monitor and controller from using an Ozonizer about 5 years ago, I had very good luck in the past using an Ozonizer so I also plan on adding a Clearwater Tech Ozonizer with my "reconstituted" system. I can obtain a 100mg unit at a very reasonable price or can "spring for a 250mg for more than twice the price. Can I use the 100mg model or will I need the 250mg for my 90 gallon tank?
<The 100 will do, the 250 mg/hour would be better.>
Any other recommendations if I want to significantly increase the Bioload?
<Am leery here... as you've enjoyed such success with "four fishes" of indeterminate species... and want to build this up to so many... need to know much more about what you have, want to add... Do study over the possibilities of what, in what order, size to place... perhaps the survey articles on "Livestock Selection" for reefs, marine systems... and many fish sections on www.WetWebMedia.com>
Thanks in advance for any help or advise
<Be chatting, soon, my friend. Bob Fenner>

Re: Ozonizer Requirements and Recommendations
Bob;
I just purchased your book!!
Lew
<Ahh, make it known if you find it useful (accurate, significant, meaningful information), and enjoyable to engage. 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>

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>

The Ozone vs. UV debate (?)
Robert,
Sorry, this is going to be along one...
I have read The Conscientious Marine Aquarist and most of the articles on your site about these two topics. I am trying to gather all the information I can about this hobby before investing thousands of my dollars and the lives of animals, but the differences of opinions is making this difficult :(
<You're telling me!>
From you book and articles, I had decided that I should inject Ozone into my skimmer. I emailed the manufacture of the skimmer I am considering to ensure Ozone compatibility and this is the response I got:
---------------------
Q: "Do you recommend the use of ozone with your skimmers?"
A: The short answer... No.
The long answer... While our skimmers are safe for use with ozone we do not recommend it's use primarily because tri-atomic oxygen or ozone (03) is a very aggressive oxidant and it can be very dangerous if not used properly.
At low concentrations, ozone causes eye irritation. At high concentrations, it may cause pulmonary edema, hemorrhage, and even death. 
<Yes... as does white bread... At the small levels of production of hobby units (at the high end, a few hundred milligrams per hour...) there is more O3 in the surrounding atmosphere from electric storms...>
In the aquatic environment it will greatly enhance the nitrification process of organics very quickly thus promoting the build up of ammonia (NH4) Nitrite (NO2) and Nitrate (NO3). 
<What? Who wrote this? Are you pulling Bob the Fishman's fins here?>
Ozone (O3) acts by transferring it's "extra" oxygen to the contaminant.
<Ha ha ha... really, I used to teach H.S. level chemistry and physics... this is the sort of material I used to grade... don't miss it>
This is, of course, undesirable and in direct conflict with the purpose of using a protein skimmer in the first place which is to remove organics before they become oxidized and then nitrified. 
<Is this all?>
While ozone (O3) is a great way to sterilize water, it's drawbacks far out weigh it's benefits especially in light of the fact that high quality ultraviolet sterilizers, when installed and run properly, are equally or more efficient and have none of the negative effects of ozone (O3).
<Hysterical... do a bit more research yourself... of the processes utilized in the ornamental aquatics interests, corona discharge and the same Ultraviolet radiation is utilized to... MAKE OZONE!>
It's up to you-
-----------------------
From your articles you are very emphatic that the "fear" of ozone is
unfounded since the levels of Ozone in use are so minimal and that UV, while beneficial, is not the best "bang for the buck".
<That is correct... that is, it is my opinion (shared by some, not all) that although UV sterilization per se is valuable as an adjunct to improving water quality in captive aquatic systems, ozone (and even ozone-generator dryers... to remove moisture ahead of the air's use in the ozone reactor) are better... ahead of UV use in value... but both are fine tools...>
My questions for you are:
Is the information about higher NH4, N02, and N03 provided by the vendor correct?
<No... you can do a bit of experimenting here if you'd like... Really... how is ozone/triatomic oxygen going to increase ammonia/NH4?, how 'bout NH4OH in solution?...>
Do you have any Ozone generators and air driers you would recommend?
<Yes, the small units made by Sanders in Germany, and the re-sold ones by Energy Savers/ESU here in the States... there are many others... mainly in Europe... Hey, take the time, save some money and read Hans Baensch, Helmut Debelius v. 1 "Marine Atlas"... about this gear... good idea... and show this to this one dealer rep.>
(I was leaning towards the Aquazone Plus 200 from Red Sea since it incorporates an ORP electrode.)
<Okay>
Is either the use of Ozone or UV really necessary for high water quality and high oxygen levels, or is a well tuned skimmer adequate enough to keep water clear and un-yellowed?
<Hmm, well, actually none, including the skimmer are really necessary... look at the Leng Sy (link on the www.WetWebMedia.com site's "Miracle Mud" type systems for instance... have none of this gear...>
Thank you for your time,
Jason Rickard
<You're certainly welcome... Keep studying my friend in fish... Don't rely on one dealer, one Bob Fenner, one anyone for what will have to ultimately be your decisions.>

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>

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
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
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

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

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

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.
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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
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.
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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 
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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