Weird Ozone Problem

d2mini

Premium Member
So a few months ago I set up ozone.
A Poseidon 200 generator hooked up to a LifeReef skimmer with ozone kit.
I was running the poseidon without an air pump because the skimmer creates some suction and with the poseidon set on low it had no problem getting my ozone up to 390 and would have easily done more if my GHL Redox probe and controller wasn't turning it off at that point.

But recently my ozone has dropped and will not go above 300. The poseidon runs 24/7. I went to petsmart and picked up a little air pump that you would normally use for an air stone and hooked that up to the input of the poseidon and it hasn't helped at all.

I've also kept up with cleaning the probe. If anything, I've noticed that as the probe gets dirty the redox reading goes up, not down. So that's not the problem.

Any idea why I can't get the ozone to raise?
 

ironwill723

New member
Can you still smell ozone being produced? The Ozotech Poseidon corona discharge cells in my experience do not last more than 6-12 months if you are not using an air dryer on the input side. I've replaced my CD cell 3-4 times already. Easy to do yourself as well. My ORP goes up as well when probe is dirty. Sounds like the cell may be bad or clogged.
 

Jamey1010

New member
Interesting than you should quote them this from page 5

"The Poseidon, when compared to other ozone generators offered in the 200 mg/hr range, outperforms them all. Based on a patented “Cold Spark” technology, the output remains constant for years"

I have a custom made "cleanzone" model from them and has worked problem free for years maybe you got a lemon power supply over powering it or maybe they did cheap out on that line but never heard people have a lot of problems with them and for the op if it's cranking 24/7 you should have no problem smelling lots of ozone and the probe could just be being finicky.

Well I've been charged $40+ by Ozotech every time I need a new one and my Poseidon is 2.5 years old. They always ask my serial number and say the year warranty is up.

http://www.ozotech.com/documents/PCSandPoseidon.pdf

Page 5 is the Poseidon generator...no warranty mentioned on that model.
 
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d2mini

Premium Member
Thank for the responses.
I can try calibrating the probe again.

It would suck if something is already wrong with the poseidon. It's only been a few months. I have an air dryer but I have not hooked it up.
It was doing great without it, even with the dial of the generator set on position 2.

I'm not sure what ozone smells like? The LifeReef skimmer is really good at recirculating the ozone and you don't need carbon or anything. I don't notice any smell in that area of my garage (fish room).

Is there any info out there on replacing the cell and where to get it?
 

slief

RC Sponsor
Premium Member
Thank for the responses.
I can try calibrating the probe again.

It would suck if something is already wrong with the poseidon. It's only been a few months. I have an air dryer but I have not hooked it up.
It was doing great without it, even with the dial of the generator set on position 2.

I'm not sure what ozone smells like? The LifeReef skimmer is really good at recirculating the ozone and you don't need carbon or anything. I don't notice any smell in that area of my garage (fish room).

Is there any info out there on replacing the cell and where to get it?

Ozone has a very odd smell. Almost metallic or something. Plug it in with the air pump on and smell the output side. You should be able to smell it on the ozone outlet side and will know it when you do. It's strong will will almost singe your nose hairs.
 

ironwill723

New member
It is very easy to change the CD cell. It is basically a metal stick with a small plug on the end and two airline tubes. The last one Ozotech sent me is actually different than the old design. The tech guy said they redesigned the CD cell recently because of issues with the old design.

I actually have two Poseidons and a BTU Mini at the moment. I've had to send all three in for service at one point or another. I don't use air dryers with mine which cuts down their efficiency and service life due to the more moist air passing through them. They work great for awhile and then just fade off in production. There is another thread on here that I posted in and someone who worked at a zoo said they had problems all the time with their Ozotech units and recommended using Del Ozone generators instead. I'll try to track it down if I can.

Here you go...

http://reefcentral.com/forums/showthread.php?t=2315524
 

wolfblue

New member
First, if you have a dryer use it. Some CD cel's will last a real long time with a good low dew point. Moisture could mean you're making nitric acid.

Probes usually drift up, but sometimes down. Though it sounds like you're not making ozone. With your air pump running, disconnect the ozone line. DO NOT stick that line to your nose and sniff. Let the generator pump ozone onto your fingertips, and then sniff your finger. Ozone smell is unmistakable, and it seems to stick to things. Like fingers. It's not good for you, but were all exposed to small amounts every day.

And, 200 mg/h seems like an awful lot for a home aquarium. The flow range for that would be 29-88 gallons per minute through the skimmer. Under 29gpm and your starting to break the foam. And you want a 2 minute or longer contact. So a 58 gallon protein skimmer?

Let the protein skimmer be a protein skimmer. Use 0.01-0.03 mg/l ozone to make it a better protein skimmer. I would turn down the gen until it never hits set point. Have the ORP peak up over 350, and let the gen run all the time at reduced output. But don't stress over numbers, ORP under 300 is fine in many cases. And don't let that thing run at 100% for now, cause it might be working. You still could have a bad probe.

--John
 

d2mini

Premium Member
I contacted Ozotech this morning and they are sending out a new cell for free! Heard back within an hour. Nice customer service.


John, thanks for the reply.
I'm a little confused about this part though.
I was running the generator on low and it had no problem keeping the orp around 390. Are you saying this is too much?
My skimmer has been working great.
And, 200 mg/h seems like an awful lot for a home aquarium. The flow range for that would be 29-88 gallons per minute through the skimmer. Under 29gpm and your starting to break the foam. And you want a 2 minute or longer contact. So a 58 gallon protein skimmer?

Let the protein skimmer be a protein skimmer. Use 0.01-0.03 mg/l ozone to make it a better protein skimmer. I would turn down the gen until it never hits set point. Have the ORP peak up over 350, and let the gen run all the time at reduced output. But don't stress over numbers, ORP under 300 is fine in many cases. And don't let that thing run at 100% for now, cause it might be working. You still could have a bad probe.

--John
I was concerned about the probe being bad and giving a false reading but everything in the tank seems to be doing fine. What would be something to look out for if I was over doing the ozone?

Thanks!
 

ironwill723

New member
Rapid breathing and scratching by the fish. Corals will close up. Sometimes excess micro bubbles stuck to all the surfaces of rock and sand. Ozone will burn your fishes gills and corals at too high of levels. Fish will die. Ozone at the 700 ORP levels will basically replicate turning your tank into bleached saltwater. I have the Poseidon on a 300g+ reef and keep the ORP set at 450 for my Achilles Tang.
 

ironwill723

New member
John...I have never heard about the nitric acid issue before. Could you elaborate more?

First, if you have a dryer use it. Some CD cel's will last a real long time with a good low dew point. Moisture could mean you're making nitric acid.

Probes usually drift up, but sometimes down. Though it sounds like you're not making ozone. With your air pump running, disconnect the ozone line. DO NOT stick that line to your nose and sniff. Let the generator pump ozone onto your fingertips, and then sniff your finger. Ozone smell is unmistakable, and it seems to stick to things. Like fingers. It's not good for you, but were all exposed to small amounts every day.

And, 200 mg/h seems like an awful lot for a home aquarium. The flow range for that would be 29-88 gallons per minute through the skimmer. Under 29gpm and your starting to break the foam. And you want a 2 minute or longer contact. So a 58 gallon protein skimmer?

Let the protein skimmer be a protein skimmer. Use 0.01-0.03 mg/l ozone to make it a better protein skimmer. I would turn down the gen until it never hits set point. Have the ORP peak up over 350, and let the gen run all the time at reduced output. But don't stress over numbers, ORP under 300 is fine in many cases. And don't let that thing run at 100% for now, cause it might be working. You still could have a bad probe.

--John
 

d2mini

Premium Member
Thanks for the info.
None of those symptoms in my tank. Everything seems to be chugging along as usual.
Hopefully its just a bad cell. Will update once i get the new one installed.
 

bertoni

Premium Member
Nitric acid is HNO<sub>3</sub>. The ozone generate will create some by converting nitrogen gas and water, so reducing the humidity of the air will help reduce the amount. Nitric acid is very corrosive, so it will damage the generator over time.
 
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ironwill723

New member
Nitric acid is HNO<sub>3</sub>. The ozone generate will create some by converting nitrogen gas and water, so reducing the humidity of the air will help reduce the amount. Nitric acid is very corrosive, so it will damage the generator over time.

Ahh I see...I thought he was referring more to some type of chemical contaminate produced in the tank water column.
 
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wolfblue

New member
d2mini.............

Running on low sounds good to me. Ozone is destroyed very quickly in salt water, but it creates other oxidants like the bromine's and even chlorine. And its these other oxidants that really do the disinfection. But disinfection by contact with oxidants is not what were after in salt water. Instead its better foam formation in the foam fractionator by microflocculation. And then increased disinfection via removal with the foam.

In the protein skimmer organic and inorganic particles of like charge will repel each other and so they tend to stay away from the air bubbles. With a small amount of ozone you can change the charge of some, so they are attracted to the foam. So we get better, stickier foam. Better foam removes bacteria and even some particles big enough for you to see. So the foam fractionator is like a chemical filter and a mechanical filter too.

But if we use too much ozone the ozone can last too long. It starts to break the carbon bonds of the long chain molecules that we want to stick to the air bubbles. So the stuff that was going to stick to the air bubbles does not. So foam does not form and those pieces of the former polar long chain stays in the water. Bacteria has to eat it now and make nitrate.

But the longer lasting ozone that broke our foam producing molecule is still going to create secondary oxidants. Now were using too much ozone and making more residual oxidants. With residual oxidants we dont want more oxidants than reducing compounds. We want the oxidants to be consumed before that water gets to animals. So we run the effluent from the protein skimmer through carbon. And the carbon reacts catalytically to destroy the oxidants.

So too much ozone reduces foam formation and produces persistent residual oxidants that may reach animals. If your volume of carbon is too small those oxidants may get through. Chronic exposure to even low levels of oxidants could lead to a reef that just doesn't seem to flourish. And it will destroy your carbon quicker than you would expect.

So we should use small, flocculation dosages of ozone in salt water. But its a catch 22 with our small under cabinet proteins skimmers. We want 0.01-0.03 mg/l ozone concentration in the skimmer for a flocculation dose. That's probably 3-10 gallons a minute with 22mg/h of ozone. But we also want a two minute or better contact in the skimmer with or without ozone. So for a 0.03 dose and a 2 minute contact we need a 6 gallon skimmer. Oh well.....

ironwill723.......

Nitric acid is the brown stuff and the reason why corona discharge cels dont last forever. We should use the air dryer. Plus your not making half the ozone your rated for with humid air. Air fed CD cells need a 70-80 below zero dew point to produce what they are rated for. It only outputs half at a dew point of-5f. And the dew point is in the 50's around here this time of year. 75% of the electricity is wasted and I'm wearing out the cells fast if I use wet air.

--John
 

bertoni

Premium Member
Ozone doesn't change the charge on compounds per se.

Protein skimmers remove primarily amphipathic and hydrophobic compounds that are not charged or not highly charged.

Charged particles seldom are skimmed because they are hydrophilic, and so are drawn away from bubble surfaces. Ozone might tend to convert organic compounds into more charged form, thus making them less skimmable in the short term. Ozone might improve skimming performance by breaking down larger molecules and allowing organisms to consume them more rapidly and produce skimmable compounds.

This article goes into a lot of details:

http://reefkeeping.com/issues/2006-08/rhf/index.php
 

wolfblue

New member
Ozone doesn't change the charge on compounds per se.
Well, it's my understanding that it will change the charge of some.

Protein skimmers remove primarily amphipathic and hydrophobic compounds that are not charged or not highly charged.

Again, my understanding is that the compounds that are normally skimmed are both, hydrophilic on one end and hydrophobic on the other end. When they contact the air bubble the hydrophobic end flips into the air and the hydrophilic end keeps the molecule oriented right at the phase interface between air and water.


Charged particles seldom are skimmed because they are hydrophilic, and so are drawn away from bubble surfaces.

Yes, they shy away from air. And the ozone can alter the charges of some so that they develop a hydrophobic end or stick to another molecule and then will stick to the air bubble.

Nobody really totally understands all this. Assumptions are made that fit observation and testing. The assumption for about the last ten years are what I describe here. Best foamfrac performance starts with a pretty low range of ozone concentration. And then you would tweak and tune from there. But at home the hobbyist won't have the resources to tune very much. So it's probably best to stay in the starter range and don't exceed 0.05mg/l by very much.

That ORP over 400 could mean oxidants. But it might not, or you could have oxidants well under 400. And at home we have no way to find out. The oxidants limit for coral I would use is 0.02 mg/l total residual oxidants. I don't think the coral would visibly react at that level. It would be a long term problem. At home you won't see it with DPD, or I think indigo trisulfonate either. I am pretty sure many people use too much ozone. I just hope they have a good volume of fresh carbon between the frac and the animals.

--John
 
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