Comet Feeder Fish Clumping Together?

Question

I have a bunch of comet fish, and recently, they've been clumping together at the bottom of the tank. What does this mean?

Answer 1

Have you tested for nitrates? If all of the fish are doing it, it's most likely a problem with your water. Chlorine and nitrate poisoning are the biggest causes of lethargic behavior, one a product of not dechlorinating your water, the other caused by not enough water changes. Do a 20% water change, add StressCoat or a similar slime-coat replacing produce and feed meaty foods like frozen bloodworms.