Bloated Cardinal

[dingweding]

I have a 4 feet community tank, all kinds fish live there healthy and happy, nearly two years now. there are a group of cardinal tetra , never had problem.

however recently I found some of them bloated, with huge tummy. but still very active and eating well. I am not sure it is eggs inside or they are too old now..

I do notice 2 already died.

any suggestion? Many thanks

 

[KittyKat]

Unless you bought old fish, it is not age. Could it be constipation? What do you feed them?

Please post a full list of water parameters and stock (including numbers).