I have 3 Cory Catfish, 4 guppies 3 neon tetra and 1 betta in my 10 gallon tank.
one of my cory catfish is the smallest of the cory and he doesnt seem to school as much as the other two. I recently found out that he has white spots on his side, top fin and back fin. He does seem happy and swims around but not as much as the others. He also seems really slim. I have already treated the tank 3 days ago with api fungus cure for my neon tetra with cotton mouth which did not make it.
dont know the alkalinity or hardness
heres a detail picture of my cory catfish