Is ozone a good idea?

[JaguarXJR7]

I currently have a 150 gallon FOWLR tank, which houses some rather heavy eaters. These incluse an imperator angel, an eel, a few tangs, etc. The nitrates generally check out very low due to a deep sand bed, an efficient protein skimmer, about 260 pounds of live rock, and a large sump. However balanced the tank may be, I am not pleased with the yellowish hue the water tends to achieve when I do not run activated carbon. I am seriously considering a red sea ozonizer with a built in ORP controller, and implementing the ozone via the protein skimmer. I will obviously run the outflow over some carbon to protect against residual ozone. I have read many articles regarding the effects of ozone, such as the oxidation of organic molecules resulting in clearer water, and possibly a more manageable bio-load for the bacteria. With a controller, what could be the negative aspects of ozonizing? I use polyethylene tubing for water lines, and I am aware of the ability of ozone to make them brittle by oxidizing the inherent organics in the plastic, but how is that possible if the outflow is passed over carbon? Is this a good idea in my situation? The aesthetically pleasing clear water is mighty enticing, as well as cleaner water for the fish.

[Randy Holmes-Farley]

Why not just continue to use carbon and add a skimmer (if you are not already using one)?

I have avoided the use of ozone due to my concerns about toxic residual oxidizing agents and concerns with overdosing. I am not convinced that carbon eliminates such concerns. If I were to use it, I would not target a particular ORP, but I would set the unit to shut off if the ORP rose above some preset level.

That said, I have also become more and more concerned about toxic organics over the years,and may consider ozone in the future. At the moment, I use GAC and skimming to help limit the levels of organics that might be attained in the aquarium.

[JaguarXJR7]

I'm sure you just overlooked it, but I mentioned in the first post that I am running a protein skimmer that seems to work very well, as indicated by very low nitrate levels. The ozone reactor I plan on buying has an ORP probe and controller that will dose ozone accordingly, allowing you to target a specific ORP for the tank. I am also concerned about the effects it might have on the plastics in my tank, such as hoses. What are your thoughts on that? I am mainly concerned about any damage it might present to the equipment... I would be extremely disheartened if the bulkhead seals in the bottom of my pre-drilled 150 happened to become brittle and leak, or any hose for that matter. Is this really a concern? By the way, Dr. Farley, I have to say that your concern and promptness regarding the reef chem forum is incredible... I can't imagine how you keep up with answering such numerous questions, and I thank you very much for your astounding service and knowledge.

[Paul B]

Jaguar, I am sure Randy knows more about ozone than me but I do not think you will have to worry about any hoses or seals in your tank. Mine has been running with ozone for over 30 years with no leaks or brittleness. Of course, the air hoses where the ozone is injected will rot in no time unless they are ozone resistant in which case they will last forever (or at least 30 years. If there is any free ozone in your water all of your animals will be dead very soon. I do not even run the water from my skimmer over carbon because ozone is so good at what it does that it does not last long enough to effect the water directly.
Of course, that is the rumor, that free ozone will do some damage and I imagine it would but I have never seen this happen.
Paul

[Randy Holmes-Farley]

Thanks, Paul.

I expect that anything that is post carbon will be OK, but that anything before it will need to be ozone resistant as Paul mentions. If you are not using carbon, then I would worry both about plastics and about the organisms, especially in the case of accidental overdose.

There is a long list of what can be produced by ozone in seawater, and they worry me a lot, but perhaps you are more comfortable with them.

Bear in mind that most everything that we use ocassionally fails. uncontrolled addition of ozone would be about one of the worst possible scenarios for a reef aquarium.

By the way, Dr. Farley, I have to say that your concern and promptness regarding the reef chem forum is incredible... I can't imagine how you keep up with answering such numerous questions, and I thank you very much for your astounding service and knowledge.


Thanks very much. :) I just got a look from my wife indicating that I've spent "enough" time online on Christmas day. :D

[jfinch]

I do not even run the water from my skimmer over carbon because ozone is so good at what it does that it does not last long enough to effect the water directly.

I didn't think it was free ozone that was the issue. I think it is other highly oxidative species that the ozone makes that would be harmful, such as hypo bromide or hypo chloride (chlorine bleach). Running the reactor/skimmer effluent through a bed of activated carbon should remove these oxidative species which is why it is usually recommended. But maybe there's a threshold limit that you've successfully kept under all these years.

[JaguarXJR7]

I appreciate all the replies, especially on christmas day. I am always one to try new ideas, and I believe I will give ozone a shot since I've seen it is possible to use safely. I will use it with great caution, though, as I am well aware of its powerful oxidation potential (oxygen doesn't like to stay tri-atomic for long). Any comments on the cleaning procedures and general lifetime of the ORP probes? I definitely want to keep it accurate, as a misreading could spell serious trouble in the case of an overdose. I am planning on buying the Red Sea Aquazone 200, with an ORP controller built in.

[Justjoe]

Hello,
Ozone is great, when applied properly and generally it would be very difficult to overdose a systems with these smaller units.
At Atlantis, I have ozone on fish and reef systems. They are set up on the smaller side so that even if there was a failure somewhere, you can never get too much ozone or residuals back into the tank. You only need a very small amount to get rid of the yellowing compounds, etc. For example, only 5 grams/hour is enough to clear the water on a 120,000 gallon shark tank when injected into a protein skimmer, 1gram/hour will clear a heavily loaded ray bay touch/feed tank.
Generally the horror stories that you hear are from multiple tank systems that are set up off of a large central ozone generator, and there is a failure somewhere in the "fail safe" system and a high dose is misdirected, and considering ozone is 10x stronger then chlorine, well it doesn't take long to wipe out everything in the tank.
If you're looking to control bacterial/coliforms, etc, then you need much higher concentrations, like ORP's in the 800's in the contact chambers.
Joe

[Paul B]

Hello Justjoe. Is that the Atlantis Aquarium in Riverhead? If it is I may have met you. My cousin was the architect that designed the place. Anyway, as I said I have been running ozone without a controller of any kind at 50/mg hr for many years and have bred many animals. If ozone is producing any dangerous compounds then they must be very minute. As for chlorine bleach, I use that in my natural seawater to purify it, it also does not last long in water (but don't add it to your reef)
Have a great day after Christmas.
Paul

[Gerard Alba]

Great thread!

[Justjoe]

Originally posted by Paul B
Hello Justjoe. Is that the Atlantis Aquarium in Riverhead? If it is I may have met you. My cousin was the architect that designed the place. Anyway, as I said I have been running ozone without a controller of any kind at 50/mg hr for many years and have bred many animals. If ozone is producing any dangerous compounds then they must be very minute. As for chlorine bleach, I use that in my natural seawater to purify it, it also does not last long in water (but don't add it to your reef)
Have a great day after Christmas.
Paul

Hey Paul,
Yes, Atlantis in Riverhead. Who is your cousin and what aspects did they design?
A small amount of ozone is a wonderful thing. Years ago I was against its use in reef tanks, but I use it on the 20K gallon tank for water clarity concerns. It would take too much carbon to achieve the same goal, and I'm not sure it would do the exact same thing. That said, I do run some carbon on the tank as well to cover the bases.
Joe

[Randy Holmes-Farley]

Any comments on the cleaning procedures and general lifetime of the ORP probes? I definitely want to keep it accurate, as a misreading could spell serious trouble in the case of an overdose.

I don't know the typical lifetime, but I would calibrate every so often to see that it is basically correct. I address some of these issues in this article:

ORP and the Reef Aquarium
http://reefkeeping.com/issues/2003-12/rhf/feature/index.htm

[Justjoe]

Another note is that some people are using ozone on a part time basis, dosing a few hours day and still achieve the goal of clear, non yellow water. It would all depend on your bioload and how heavy you feed the fish/corals, etc., but I think a part time use of ozone on a reef/fish tank with a moderate to low fish load is a very efficient method of using ozone.
Joe

[Boomer]

Jaguar

Randy asked me to drop in for a few comments. I see there are already allot of good ones here and you are taking precautions and have checked things, so I'll try to be short ;)

If the ozone is posted tread with GAC IMHO there is no issue. The reaction of ozone in seawater gives ozone a half-life measured in seconds. The plastics that turn yellow and breaks down are the cheap plastics used in some skimmers, where the ozone is being used. I have never seen a real concern with cell cast acrylic skimmers, which most are made of now. What is really leaving the skimmer is not ozone but what Jon pointed out, bromine bleach, which has a very long half-life and can accumulate if the water is not posted tread with GAC. It is quite toxic, small amounts can kill urchin larvae.

I'm glad you are using a controller, the only way to go. Set it for 350 mV cut-off. You don't need to go higher. 400mV is the max IMHO. STD ozone levels are 0.3-0.5 mg / net gals/ hr.

Some things you have not mentioned yet and maybe missed or are unaware of. The feed ozone, from the ozonizer, should go through ozone proof tubing. You need an air dryer. Humidity has a great effect on ozone. A humidity of only 30 % will drop the output of ozone 15 mg / hr, meaning a 55 mg unit will drop to an output = 40 mg unit with no dryer. As humidity rises it gets worse.

Like Paul, I ran ozone for years, actually 2 decades, without any GAC but those aren't reef tanks. I do not what anyone running ozone with out post GAC, it is like an accident waiting to happen.....and for some people it has happen.

If you want to use ozone do it right and it looks like that is what you want, more than I can say for many :D Ozone can be a benefit if you know what you are doing and understand it. It should NEVER be just hook up the ozone unit and let it rip. :( I might add it also increases light penetration.

edit

More :D

Get yourself a good chlorine test kit, as it will test positive not only for ozone but also bromine bleach ;)

[Randy Holmes-Farley]

Thanks for popping in, Boomer. :)

[angelo68]

I just bought a ozone generator and a orp controller. I intend to run the ozone line into the air input of my beckett skimmer. The return line of the skimmer dumps into the sump. I have a rainbow system with a chemical module, so I will put some hydro carbon in there. Should I put some of the carbon on the outstream of air from the skimmer. And where should I place the orp probe, before/after the carbon? The generator is a 200mg/h. I have a parrott in my house, is ozone dangerous to it's health? Even if all precautions are addressed?

[Randy Holmes-Farley]

I would have all of the water that was exposed to ozone pass through carbon before going on to the tank.

I don't know about the air stream and how to best block any ozone release. I'll leave that to the others to comment on.

I'd put the ORP probe in the sump or main tank, after any carbon.

Ozone is dangerous to people and parrots if it is being dumped into the room. I don't know which is more sensitive.

[Boomer]

Should I put some of the carbon on the outstream of air from the skimmer

Yes, this will remove any Ozone that may escape into the room, a little often does. The parrot will be the most effected.

[DonJasper]

Originally posted by angelo68
I have a parrott in my house, is ozone dangerous to it's health?

http://www.epa.gov/airnow/health/smog.pdf

I didn't see "Parrots" on the "Who is most at risk from ozone?". But I do know about "Canary's in the mine shaft" :) I'd suggest you keep our parrot away from those electrostatic air cleaners that Sharper Image (and everyone else) likes to sell. Or maybe run thier output through GAC! :lol:

[JaguarXJR7]

Thanks for all the information... the replies have been very helpful. I have already planned on buying ozone safe tubing for connecting the ozonizer with the skimmer, and the intake air will pass through a 250mg air dryer, provided by Red Sea when I buy the ozonizer and controller. Will I need an air pump to push air though the air dryer, or can the skimmer just pull it through the whole setup? I will constantly run activated carbon, and monitor ORP readings very closely. My tank has no invertebrates of any kind, so the change in light penetration as the water clarity increases will not be an issue. I am still hoping for someone to let me me know how to clean and calibrate an ORP probe, but I have already received so much information from you all that I cannot complain. If anyone has any information on this, or any additional comments, please feel free to chip in. Thanks everyone.

[Boomer]

Randy gave some in his article he posted above

ORP Standards

Many ORP meters do not permit calibration, but some do, and for detailed ORP measurements, including situations where ORP is being controlled (such as when using ozone), it is worthwhile calibrating (or checking the proper operation of) the meter. Usually, the calibration is quite easy given commercial ORP standards. A variety of standards are available, including Zobell solution which can be obtained from Cole Parmer for $21. It is a solid that is reconstituted from deionized water, and has an ORP of 231 ± 10 mv. Another common standard ORP solution involves putting quinhydrone into pH 7 and 4 calibration solutions to make standards of 86 and 263 mv, respectively. A third standard is Light's solution, which uses the Fe++/Fe+++ reactions described above.

ORP calibration

http://www.sensorex.com/products/orp_electrodes/ORP_sensor_products.html

ORP probe cleaning.

http://www.fondriest.com/technotes/phclean.htm


More

http://www.americansigma.com/support/downloads/332889.pdf

DO NOT USE A TOOTHBRUSH, I DON'T CARE WHAT ANYONE TELLS YOU. Use a cotton swab stick, like the ones you clean your ears with.

Will I need an air pump to push air though the air dryer

Yes, if it is a air stone operated skimmer. If it is Venturi action then usually no.

[McGinnis]

Randy or Boomer,
Maybe you guys can help me with this. Last night I noticed a strange smell from my tank, something I could not identify but related to the removal of a large bag of carbon I had in the sump. I run ozone in my skimmer, and turned the reactor off as I thought this could be a smell associated with some biproduct of ozone production being released into the air. I run 10 mg/hr of a Red Sea 50 mg/hr unit. I also use a fairly large air pump, rated at 60-90 gallon tanks. Could anyone elaborate on what could be happening. At the time of the smell I had also cleaned the skimmer. If you all need any more information let me know.

[Randy Holmes-Farley]

Ozone does have a smell.

Can you describe the smell?

[McGinnis]

Well, it is kind of hard to describe. I have no idea what is causing it, but it is pungent! I mean, it is not a smell that can be attributed to anything else in the house. When I opened the stand doors it came out, and I have noticed it since. Is ozone really hazardous at lower levels? It kind of smells like a fax macine or copier! I just went and checked and it is close!

[Randy Holmes-Farley]

That may well be the ozone. I believe that ozone is hazardous at low levels, yes, but I have not really investigated it yet. I'll be writing an article on it in early 2006, and will have more details then, but I know that doesn't help you now.

[McGinnis]

I cannot imagine that that is good! I really don't know why it would all of a sudden start having some issue with production. I had it going for a few days, and just recently changed to PinPoint probe because I thought the Red Sea one was off. Hmmm....Well, I am not going to take a chance and have it flooding our place all the time, so I guess I will just disconnect it for now. Is there any advantage aside from cleaner water and great skimmer efficiency to ozone that I will be loosing?

[herefishyfishy2]

McGinnis,

Sounds like ozone smell to me. At low levels it can possibly be harmful and may cause you to be lethargic at higher levels. I have the same sized Red Sea unit and run at about the same level on my 75gal tank. Do you have any leaks in the tubing? I have not smelled ozone in quite ahwile on my tank and only when I ran higher levels.HTH

[Billybeau1]

Jag, You've already got great advice. He's my .02

Get an ozone safe check valve to put in line with the tubing going to the skimmer. They're cheap and good insurance.

Upgrade your drier to the 500 mg. Otherwise yo'll be cooking beads once a week. Trust me I know. Its a PITA

The ORP probe that comes with that unit cannot be calibrated. Once its bad, its bad.

All in all, I've had good luck with my unit, so far. I have the one you're buying. The water clarity is astounding. Although I use a UV sterilizer as well and think that helps too.

I made a homemade cup to put carbon on top of the skimmer and I run a carbon unit on the output of the sump line returning to the tank.

Good luck :)