Ozone Deaths - Brainstorming

[Slider162]

Recently thought I would give ozone a try. Seems like the smallest generator available is the Poseidon 200 which seemed like overkill. I ran across the Certizon C50 on eBay which seemed like a perfect fit. At first I wasn't seeing any results. The Quantum 120 just wasn't pulling from the ozone inlet. Might be because the way I am piping in fresh air to try and keep my PH up. So I connected a Hygger Ultra Silent 1.5W Fish Bowl Aquarium Mini Air Pump to the C50 at 30-40% to force air into the skimmer as a test. I immediately started seeing results. So I programmed it in to run overnight with a ORP 360 cut-off. I had carbon on top of the skimmer but I did not have any carbon on the output of the protein skimmer. I hadn't figured that part out yet. There aren't any reactors to attach to the output of a skimmer, or at least I couldn't figure it out at the time.

I thought I was being conservative. I bought a small C50 ozonator and ran it at 30-40%. A ORP 360 cut-off. Just a few hours overnight. When I woke up, my Flame Hawkfish was dead and Kole Tang was barely hanging on and passed shortly after. Two clowns, Royal Gramma, two peppermint shrimp, pistol shrimp, LTA, and all coral appeared okay. I did a 25 gallon water change and threw some fresh carbon in the sump and hoped for the best. A week later and everything else seems to be okay.

Red Sea Reefer 250
Custom Bashsea SMS 30-15 Sump
Nyos Quantum 120 Skimmer
Sander Ozonizer Certizon Model C50

What killed the fish? Was it the sudden change in ORP? Was the ORP cut-off too high? 15-20mg/h too much for a Reefer 250?

This past week I have been working to design a reactor that is custom fit to work with the Quantum 120 Skimmer. Here is where I am at printed out of clear PETG. The sources I looked at said PETG was ozone resistant.

It has to be better than nothing, right? It should hold at least a cup of activated carbon in a bag. It should still have some movement as long as it isn't packed too tight.

 

[KrisReef]

I don’t know specifically the activity of o3 but AI has a similar recollection, which should help answer the question.

AI Overview


Ozone causes fish death when an excess of residual ozone gas or toxic oxidizing byproducts enters the aquarium water and chemically burns the fish's delicate skin and gill tissues, leading to suffocation or ozone poisoning. [1, 2]

 

[Jay Hemdal Verified Community Expert]

Recently thought I would give ozone a try. Seems like the smallest generator available is the Poseidon 200 which seemed like overkill. I ran across the Certizon C50 on eBay which seemed like a perfect fit. At first I wasn't seeing any results. The Quantum 120 just wasn't pulling from the ozone inlet. Might be because the way I am piping in fresh air to try and keep my PH up. So I connected a Hygger Ultra Silent 1.5W Fish Bowl Aquarium Mini Air Pump to the C50 at 30-40% to force air into the skimmer as a test. I immediately started seeing results. So I programmed it in to run overnight with a ORP 360 cut-off. I had carbon on top of the skimmer but I did not have any carbon on the output of the protein skimmer. I hadn't figured that part out yet. There aren't any reactors to attach to the output of a skimmer, or at least I couldn't figure it out at the time.

I thought I was being conservative. I bought a small C50 ozonator and ran it at 30-40%. A ORP 360 cut-off. Just a few hours overnight. When I woke up, my Flame Hawkfish was dead and Kole Tang was barely hanging on and passed shortly after. Two clowns, Royal Gramma, two peppermint shrimp, pistol shrimp, LTA, and all coral appeared okay. I did a 25 gallon water change and threw some fresh carbon in the sump and hoped for the best. A week later and everything else seems to be okay.

Red Sea Reefer 250
Custom Bashsea SMS 30-15 Sump
Nyos Quantum 120 Skimmer
Sander Ozonizer Certizon Model C50

What killed the fish? Was it the sudden change in ORP? Was the ORP cut-off too high? 15-20mg/h too much for a Reefer 250?

This past week I have been working to design a reactor that is custom fit to work with the Quantum 120 Skimmer. Here is where I am at printed out of clear PETG. The sources I looked at said PETG was ozone resistant.

It has to be better than nothing, right? It should hold at least a cup of activated carbon in a bag. It should still have some movement as long as it isn't packed too tight.

Although I can't be certain, it does sound like residual ozone-oxidants were the culprit here. I don't like to rely on ORP as the sole measure of this, some ORP probes are inaccurate, or not calibrated properly. I like to use a simple chlorine DPD test to measure residuals, and then, when starting ozone, I only run it during the day while I can test for residuals. Any pink color in that test is bad - adding sodium thiosulfate (dechlor) can counteract that issue.

This document might help: (click on the PDF link to the right side of the screen)

https://www.reef2reef.com/ams/ozone-use-in-marine-aquariums.1078/

 

[KrisReef]

Since you have Orp monitored, I would recommend setting up the input at the lowest possible dose of ozone and forced air and slowly ramp up until you detect the increased in ORP.

Looking for improvement in water clarity or other effects may not be visible at first, so let the system acclimate to the initial detectable bump and see how it performs at that level before depressing the throttle to the floor.

 

[Privateye]

Ozone is particularly dangerous in saltwater. It's not so much the ORP you need to worry about, it's the bromate. A typical pool chlorine test should be able to read the concentration (even though they're for chlorine). The number I've seen thrown around is you want to keep the bromate/hypobromous acid below 0.05 ppm.

I can confirm from experience that an ORP of 360 will likely impact your fish's gills and mucus. In the past I worked with some purge systems that would cycle on at 300 and off at 350. The fish had very little mucus on them, and the tips of the gill lamellae were grayish. We were raising a hardy freshwater species though.

Between the risks to the animals and the risks of running ozone in your house, I generally discouraged aquarium customers from adding these systems to their tanks. It's a really powerful tool and it can work well, but it can also go awry quickly. You'll also need to ensure the fish get enough iodine from their diet or they can develop goiters.

I'm sorry for your losses. It's never a fun story to hear.

 

[Slider162]

Thanks for the replies. I thought I was being cautious. I feel horrible. I'm embarrassed, but I just needed to know more about what happened and maybe someone else can learn from my mistake.