One of my emerald green cory catfish seems to be dead but still moves slightly if i try to touch him. Though he doesn't try to get away if i net him like the others do. He seems really thin and doesn't move at all. I first noticed this today when i found him on his side and thought he might be dead. I don't know if he has a disease or if he is just lazy. The others all look fat and lively its just him. Please help and thank you for your time.
Water is clean. PH: 7.6, Ammonia is 0 ppm
, Nitrite is 0 ppm
, and nitrate is at 0 or 5 ppm
It's a 10 gallon planted tank and it's been set up about 5-6 months
Filtration is bubble filter tetra whisper 10 .
Fish 4 emerald cory catfish babies(like an inch), 4 neon tetras which are new.
I do water changes twice a week the last one was Saturday.