To O3 or not to O3 (Ozone)?

[NaCl_H2O]

It has been awhile since I caused any trouble, so what the heck :P

Who uses an Ozone generator? Like it?
Who is considering it? Why?

This is something I have considered for some time now, and ~Pete~'s interest is now being peaked too. Below is a thread on RC for those that want a little background.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=517084

So ... O3 or nOt?

[Richard]

Ozone works. Of course there are other ways to get the same results but if you don't mind spending the money then go for it.

I have run an ozonizer without filtering the water through carbon afterward without a problem but you should really try to have a setup that uses carbon because in saltwater ozone can create things like bromine and chlorine. Plus residual ozone getting into your tank is not a good thing.

Also you need to have the air coming out of your skimmer or ozone reactor filtered through carbon also. Most auto waste collectors are setup to do that. Ozone likes to make plastics very brittle over time so if you don't you'll end up ruining things in the area like power cords.

Here's lots of info on the use of ozone...
http://www.fisheries.nsw.gov.au/aquaculture/extension_services2/use_of_ozone_in_recirculating_aquaculture_systems

[TexasTodd]

I've been using it for about 2-3 weeks.

Here's what I found it boiled down to:

Ozone or UV help break down organics in your system that are then more easily pulled out by your skimmer(s).

UV is safe but the GOOD units are very expensive and require annual bulb replacement with a gradual slowing of flow through them as the bulb wears. FOR ME the largest factor is the HEAT that UV puts in. The best ones are HO 80w or 120w and up. We all know how much heat a bulb like that puts off. Now think of it being submersed in you water.

Ozone---get the units without bulbs! RedSea and a couple others use a different method so there is no bulb to replace.

They are not all that expensive. My 100mg RS unit was like $220 and it has no disposables to replace.

Most on Reef Central have found this equation to be the best to run: 0.18mg for every gallon of system capacity and run for 4-12 hours a day.

GET A LARER CAPACITY UNIT THAN YOU NEED. Living where we do and plus the humidity of our fish rooms-----the air dryers for these units last about 2-3 days. For me this is unacceptable. I posted on RC and had several replys that without the air dryers in line the 03 units are right at about 50% output of what they would be with an airdryer--------------------------------solution is just double the ozone rate and don't use a dryer. Many people were doing this and had for a long time.

I run mine in to one of my skimmers that is in a sump at the end opposite of the return. I have not been using carbon.

I didn't know about 03 causing some unwanted chemical changes possibly in saltwater..........I'd like to hear more on this and what kind of volumes it makes.

If you use carbon and are running SPS corals it shouldn't go more than 2 days between changes as it becomes like filter floss and starts creating more PO4 in your system. So that is an issue.

I spoke with a couple of different skimmer manufacturers and both said it should be a LONG time before 03 would do damange. They said O-rings are usually the main thing and they can be replaced cheaply.

The O3 is also supposed to really keep your water clear which is HUGE in the efficeincy of your light penetrating to your corals. Goes back to the old test of: clean your glass inside and out on your display tank. Stick a white piece of paper at one end and look "length wise" from the other end at the paper........should be pure white. Or, next water change look at a full bucket of your pulled tank water in a white bucket......it should look clear to slight blueish........no yellow or green.

FWIW just my opinions and some findings from research. I kept SPS corals for a long time without O3.

Todd

[TexasTodd]

Nice link Richard. Thanks!

Todd

[GaryP]

Correct me if I'm wrong but don't you use two sets of carbon with an ozonator? One for the air coming off the skimmer and one for the water.
The one for the air shouldn't be a problem as far as phosphates are concerned however they do recommend a different kind of carbon for vapor phase then we normally see at an LFS. The vapor phase carbon is primarily for the protection of the home's inhabitants.

I use both carbon and phosphate remover to solve the problem of carbon leaching degraded phosphates. Water first passes through the carbon and then through a layer of Phosguard before leaving my carbon filtration unit.

Ozone is very commonly used in Europe but has never caught on here. They also use it for drinking water treatment instead of chlorine, like we do in the US.

I have read that it does increase the effectiveness of skimming but I can't really understand why. Martin Moe talked at great length about this in his book. As hydrocarbons are broken down into shorter chain length they become more water soluble. Water soluble compounds are not removed by skimming. The way that skimming works is that these waste molecules have a water soluble end (Hydrophilic) and a non-water soluble end (Hydrophobic). The non-water soluble end is attracted to the air bubbles. The farther these two ends are seperated, the more readily they are skimmed.

It could be that ozone just chews these waste molecules up so that they are more easily digested by bacteria. Think in terms of digesting proteins vs. sugars and you will get where I am going with this.

[TexasTodd]

Great information Gary.

I think it's the breaking up of the chains you mentioned that allows the other part of the chain to be skimmed out.

Bomber in RC I think talked about UV breaking them in to skimmable and unskimmable parts.(?) I could be wrong though.

I think quite a few people using O3 on RC do not use carbon. Something about the hobby level units not putting enough out to be dangerous.

Todd

[Richard]

The carbon for the air does not need to be replaced often. Carbon does not actually remove ozone but just gives the ozone something to react with. The thing to remember is the oxygen does not want to be O3.

I don't have any info on how much chlorine, bromine etc ozone can produce. You can avoid all that by keeping your mg/l low enough so that there are always some organics present for the ozone to react with. I think you only get into trouble if you really crank up the mg/l. Then it can start reacting with chloride, bromide, etc. and start creating some bad stuff.

I've been told that you can just have the water filtered through a dirty filter pad and that will get rid of residual ozone as well.

[TexasTodd]

Ah, thanks Richard. That makes sense.

At the low mg per gallon most are now running their 03 at, and only part of the day; my guess is you don't use up all the organics.

Todd

[GaryP]

That reminds me of what is done with drinking water treatment. All waters have a unique value called its "chlorine demand." That is the amount of chlorine that will react with the oxidizable materials in the water before enough is added to establish a residual. The actual residual the water utility shoots for is low, usually around 0.5 ppm. If the chorine demand is 100 ppm, that means that you have to add 100.5 ppm to get a .5 ppm residual.

OK, so what does this have to do with ozone? Everything! The same principle applies with ozone treatment. You want a small residual. You would dial in the ozonator until there is a small residual left. I've never ran an ozonator but I am familiar with how they work. The trick is to find a test kit that has the necessary sensitivity to determine the residual level with some precision.

The other issue is that the demand is going to change during start up. The demand should go down as the organics present in the water are digested so a lot of testing is going to be needed initially. I might suggest using carbon in the beginning until the system reaches some degree of equilibrium. Admittedly, this is a challenge and is probably to much of a challenge for most hobbyists. That's probably why you don't see ozone used very often in the US.

[NaCl_H2O]

Gary, the units for sale come with an ORP monitor, which as I understand it does relate somewhat to residual Ozone ... meaning you could drive the ORP up to 400+ I think, but I think you set these around 380 which means organics are still present to react with residual Ozone.

Do you think this ORP monitoring is a reasonable approach to controlling Ozone dosage?

Also, how "Calibration Sensitive" are ORP probes? I know I wouldn't trust a PH probe to automatically control SQUAT since what I have learned from you on how they operate!

[GaryP]

ORP stands for oxidation reduction potential. It doesn't really measure ozone, but rather the electrical charge of the water. Oxidation means the potential to donate electrons while reduction means its ability to accept electrons. Obviously, having an oxidizer present like ozone will increase the ORP, but it does not measure it directly.

I have never ran one and don't know how good its going to work in a continous regulating mode. I would suggest going to RC for some feedback on it.

[Richard]

You don't have to calibrate the ORP probes. Just keep them clean. I don't remember how often you have to replace them. One thing I noticed with mine was that a new probe always read a very low ORP for the first week or so. I always turned off the ozone until a new probe "broke in".

Generally the ORP will run higher with cleaner (less organics) water. That is how the ozonizers with ORP controllers work. You would just set how many mg/hr of ozone you wanted it to produce and then set the ORP controller to say 350 mv. When the ORP reaches 350 mv then the unit stops producing ozone until the ORP drops below 350 again. The only weird thing I ever noticed was that freshly mixed SW always had a really low ORP, I don't know why that was.

FWIW, Someone pm'd me asking about the other ways to get the same results. Here was my answer...

"Well you can do a bunch of water changes, change carbon frequently, use other chemical filtration such as polyfilters, purigen etc.

Or you can do what I do and just use a deep tri-pelletized carbon bed in a fuge. FWIW, I have a $250 ozonizer under my 215 that I have my deep carbon bed on...it's not even plugged in. I haven't had a reason to use it."

[NaCl_H2O]

So Todd, you didn't comment on any noticable improvement in water clarity?

I'm seriously thinking about this, I really hate cleaning the glass sleeves constantly on my UVs, what a pain! That plus I need to spend about $125 to replace UV bulbs in the next few months!

Some of y'all have seen my setup. If I use ozone in my TurboFloater 5000, the return from the skimmer travels back to the sump and travels a good 12' through the sump system (not fast moving water at all) before it reaches the return pump. With this configuration, and low Ozone dosing as todd suggests, couldn't I omit the carbon, assuming there would be plenty of contact with organics before it reaches the return pump?

With the RedSea units, is some type of airpump needed too, or is that incorporated into the RS units?

Thx - Steve

[NaCl_H2O]

I needed to order UV replacement bulbs, so I ordered the RedSea 200 unit instead ... I'll post results in a few weeks.

[TexasTodd]

Well, I did a big-long response and if vaporized somehow when I posted.

I've been gone with no computer.

Yes, water seems clear. I'd do it again.

RS 03 units are supposed to be used with an airpump. But some on RC place their units close to their skimmers and let the skimmer draw through the unit with the skimmer's suction---whether the 03 is on or not.

Todd

[NaCl_H2O]

Ok, got it all hooked up without an air pump, seems to be doing fine.

ORP questions:
1) How long before I can trust the ORP probe?
2) Reading 275 already - seems to good to be true?
3) What's the right ORP target ... 300mV?

Less than 24 hours and the dryer is almost exhausted already - glad I bought the RS 200 unit ;)

[TexasTodd]

Yep on the larger unit without the air dryer!

400mv is the target most go for. The probe should be working right out of the box. What happens with an ORP prob is different than others.

On a PH probe if you don't clean it the probe will start to say your PH is LOWER than actual. With an ORP probe it's the oppisite. If you don't clean with vinegar about 1x a week it will show your ORP HIGHER than it really is.

Also, ORP will always be higher in the moring because as the PH rises the ORP falls.

Todd

[NaCl_H2O]

Ok, one week in operation and I think I'm gonna like this :D ORP was about 260 when I conected it, now at about 320 and the Ozone generator has been running 24x7 trying to get ORP to 350. Been slowly increasing the O3 generation level.

I did add Charcoal to the top of the skimmer for the air coming out of the cup - just too much O3 smell for me. The charcoal cured that immediately.

Skimmate volume is maybe slightly greater, but much more dark/thick. Water clarity is outstanding, corals look a little better (I think :unsure)

Definately more convenient and maintenance free than the UV units!

[TexasTodd]

And less heat!

It will make your skimmate smell REALLY bad.

Remember you need to clean the ORP probe at least once per week in vinegar or it will show your ORP reading HIGHER than it actually is.

TT