3 fish dead within 24 hours of upping NoPOx dose?

[nbd13]

Hi,

I lost 3 fish. Powder blue tang, lineatus and joculator.

have 10 other fish

Established 150 gallon reef tank, all fish have been in for over a year.

Fish are all fat and healthy. I mean really fat. I’ve been adding NoPOx for about a month now. Total volume is about 160 gallons. I was adding 20 ml of NOPOX daily.

I upped that to 25 ml for the last few days then stupidly added 35 ml this morning.

On apex the ORP dropped big time from 412 to 350 this morning. Wonder if that did it?

I have carbon in the sump. Air stone in the tank. And power heads pointed at the surface. ORP is up to 370.

Planning on a 35 gallon water change tonight. Once temp is up and salt mixed.

Thoughts??

 

[Jay Hemdal]

I've never used the brand myself, but it is apparently similar to carbon dosing with acetic acid and ethanol mixed together Dosing that will cause a bacterial bloom (part of the process) which in turn utilizes dissolved oxygen (as I think you know). The reduction of the carbon by the bacteria uses oxygen, gives off CO2 and depresses the ORP.

Did the three dead fish die with their mouths agape? That is a clear clinical sign of anoxia.

The only thing that doesn't match up is why the other fish are fine. Not all fish have the same dissolved oxygen requirements, but reef fish, overall, seem pretty similar in their oxygen needs. I do know that some reef fish are better at seeking out areas of high dissolved oxygen than other fish are. In addition, it could be that the three fish that died were compromised in some way - and were able to manage when the oxygen level was normal, but couldn't compensate when it dropped.

Jay

 

[nbd13]

I've never used the brand myself, but it is apparently similar to carbon dosing with acetic acid and ethanol mixed together Dosing that will cause a bacterial bloom (part of the process) which in turn utilizes dissolved oxygen (as I think you know). The reduction of the carbon by the bacteria uses oxygen, gives off CO2 and depresses the ORP.

Did the three dead fish die with their mouths agape? That is a clear clinical sign of anoxia.

The only thing that doesn't match up is why the other fish are fine. Not all fish have the same dissolved oxygen requirements, but reef fish, overall, seem pretty similar in their oxygen needs. I do know that some reef fish are better at seeking out areas of high dissolved oxygen than other fish are. In addition, it could be that the three fish that died were compromised in some way - and were able to manage when the oxygen level was normal, but couldn't compensate when it dropped.

Jay

thanks Jay.

Yes the fish had there mouths open.

Maybe I should’ve spread the dose out instead of dumping it all in at once. Maybe that’s where I went wrong. Should’ve spread it out. I dumped it all in first thing this morning left for work and when I get home come home to 3 fish dead.

2 borbonius anthias and 1 blenny look rough. Breathing heavy in the rock work.

Purple tang, bandit angel, regal angel, 2 clowns, conspic angel, 5 damsel look ok.

Fingers crossed no more losses. Getting ready to change water now.

 

[User1]

Initial dose has to be calculated based on water volume and not size of the tank. So aquarium and sump less substrate, rocks, etc. There are a few calculators out there to help if you don't know or already know.

When I used the product, and it works, I calculated size and dose then reduced by 1/3 to be safe. There are enough threads around about this stuff bottoming out nutrients quickly and causing other issues. Not product related but hobbyist induced.

Do you run a skimmer? You must have a working skimmer.

Needs to be dosed daily. If you miss a day or dose you do not double up. You continue as if you dosed it.

If you increased by 10 ml in a day my guess is that was too much. The product is supposed to be dosed over time with a slight increase as you test water chems.

 

[Jay Hemdal]

thanks Jay.

Yes the fish had there mouths open.

Maybe I should’ve spread the dose out instead of dumping it all in at once. Maybe that’s where I went wrong. Should’ve spread it out. I dumped it all in first thing this morning left for work and when I get home come home to 3 fish dead.

2 borbonius anthias and 1 blenny look rough. Breathing heavy in the rock work.

Purple tang, bandit angel, regal angel, 2 clowns, conspic angel, 5 damsel look ok.

Fingers crossed no more losses. Getting ready to change water now.

So - I’m concerned that some fish still look rough; usually when aeration is restored the symptoms alleviate fairly quickly...
Jay

 

[malacoda]

The recommended dose (for FOWL) is 3ml/day per 25g of water volume ... and just 1-2ml/day for a mixed reef or SPS dominant tank.

At 150g ... assuming that is your total water volume ... the recommended dose would be 18 ml/day. So at 25 ml/day you were already significantly past the recommended dose. Not necessarily a bad thing as you increased from 20 to 25 gradually...

But that final sudden jump of another 10 ml in a day was a HUGE, sudden increase.

A large, sudden drop in available oxygen for the fish would definitely be my primary suspicion. And I even wonder if it was so much that, even with the airstone, the bacteria are still out competing the fish for the added oxygen as they continue to consume the current abundance of carbon.

As the carbon is depleted and your ORP gets back up further, hopefully they'll begin to breathe easier.

 

[nbd13]

Thanks guys. Oversized Skimmer is running.

I just changed 30 gallons of water. Have 2 power heads in the sump point up to agitate the water. Air stone in the display.

Fingers crossed I do not loose anymore fish through the night. I am making RODI water through the night and will change 30-35 gallons again tomorrow.

Anything else I can do? Obviously I’ll stop nopox for a week or more.

really sucks. I have had some of these fish for almost 2 years.