my mono is like 8 in and i just went to feed them and he has a cut on the inside of his mouth on his tongue like thing....it seems to almost be swollen because he is breathing out of his mouth and not closing it fully....i only had enough salt to treat the tank 1/3 of the recomended dose.....it almost looks like a blood blister type hing...i will see if i cab get some pics....alll my water params are fine...hes in a 125g with a fx5 for filter