Backyard Aquaponics
A place to discuss aquaponics

Can someone help? This morning we had three almost dead fish. They are silver perch - one small, one medium, one large about 5". They're still alive but not swimming. I have them in my net now, they were laying on the bottom of the tank on their sides.

The water tests are all good, ph is almost 7, water temp is 16. Nothing else has changed.

We've emptied some of the water out and added fresh rainwater. The fish, which are usually scared of us and on the opposite side of the tank, are now swimming close to the top or on the side of the tank near us. They were last fed at 6am.

We stopped running the pump at night about a week ago. Could this cause a problem? Could it be a lack of oxygen?

Any suggestions most welcome.

If you think its lack of oxygen (and sounds like it could be) then get a bubbler into the tank and see what happens.... or agitate the tank.

Anyway you can turn your flow up so that your return creates a greater oxygenation??

we've had the aerators going all morning.

are the others gulping at the surface?

they're not gulping but some of them are swimming near the surface. They're kind of dopey.

are any of them flashing? that is when the fish scrape their sides across the floor of the tank. If lots are doing that you could have an ammonia problem.

none of them are flashing now but they have been the past couple of days. Ammonia tests are ok, so are nitrates, nitrites and ph.

no other changes, additions, modifications etc..... ie different feed brand??

no changes. same feed.

hmmm, I don't know. Hold off feeding them for a day or three. Keep the aerators pumping, keep running the system to keep it clean.
Sorry I can't be more help Rhonda. Maybe one of the brains of the operation will check in soon with some other advice.

ok, thanks.

Yes, sounds unusual Forest... but unfortunately very difficult to know what it might be.. Keep the system pumping at night, try putting the almost dead ones into a seperate container of fresh water to see if they perk up..

thanks joel. They're in a separate container. Six dead now.

I just checked my ammonia tests with a different tester kits we have here. Same results, ammonia is ok.

Have you got any salt in there forest? If not get some ready in case it is a disease or ammonia spike. I would test the vitals, Ammonia, Nitrate, Nitrite.

Hummmmm.... last time a similar mystery fish kill took place was I think with F&F.... think everyone eventually came to the opinion that it was probably caused by wind carried overspray from insecticides used....

Haven't done any spraying... or anyone in the neighbourhood that you know of???