Backyard Aquaponics
A place to discuss aquaponics

I have sadly suffered a total fish loss in my 4 month old system. My existing fish had seemed healthy and fine. I added some new fish, and apparently they brought a disease with them, because the entire system died off in a few days. Some kind of brown spots were on the fish.

Ammonia, nitrites, and nitrates are all at zero. PH is 6.8. I have four large airstones going in the tank, and while I don't have an O2 tester, if it was lack of oxygen for the increased number of fish, the problem should have corrected itself as the population dropped. I had just added some chelated iron. Though I had done that before and it didn't seem to cause issues.

Unless I missed something, my biggest question at this point is how long I should wait before adding new fish. I don't want to add fish to a diseased tank, and repeat the process. I imagine adding an antibiotic would undo all the good bacteria I have finally built up.

Can't help you with this one. It's impossible to say without knowing what the disease is

I did some research online. While I'm not 100% sure, this picture seems to match what I saw on the fish. If correct, it may have been CCVD, channel catfish viral disease.

I may have sort of found my answer.

In pond water the virus persists for about 2 days at 25°C and about 28 days at 4°C, but somewhat longer in dechlorinated tap water. (Plumb et al., 1973).

Forgot to offer my condolenses about the fish losses.

Glad you found the information you needed about the disease and it looks like a relatively short wait to get going again

Catfish have been pretty finicky for me in my AP setup here in Oregon. They seem to be very prone to problems because the water temperature isn't as high as they like.