Apistogramma fry die off

[mooman]

I have a 20g long with about 40 apistogramma panduro fry from 5-15mm long. They get twice daily bbs and weekly 40% water changes. A few have been scooting along the bottom (maybe 3 or 4). I figured they just needed culling.

Came in this morning and a few were hovering at the top and 4 of the smaller ones were dead. Temp good. No detectable ammonia, nitrites and nitrates were under 5ppm. I did an immediate 60% water change.

The only thing i can think is the bbs i fed them yesterday. The tank is in my classroom. On weekends I start a batch of bbs on friday before I leave. By monday morning they are suffering a die off, but i just separate out the ones that are alive and feed those. Could bbs be the culprit? Any other ideas?

 

[Mike Wise]

I can't say for certain, but I doubt live BBS would be the problem. My guess is that the tank is becoming too overcrowded for the filter to keep up. Maybe some fry died and this started a chain of pollution related fry losses. If it were my tank, I'd do just like you did - a large water change - and keep an eye on everyone. Stress can lead to illness.

 

[Phile]

Make sure that there are plenty of hiding places for the smaller fry to get to, so that they can avoid the larger bullies. If that doesn't work, split them up. You can use large cheap plastic storage containers. Plain, clear, flat sided ones are perfect and can be found at discount stores for not too much. Keep it bare bottom, a bunch of plants and a sponge filter, and some hiding places. You can then sort the fish by size if there is starting to be a large differential. The containers are easy to clean and store when you're done.