Well my flowerhorn was sick with hex last week and he dident eat for 4 days, I raised the temp and put Epsom salt in the tank. He started eating again for 3 days and was feeling better, I did A water change last night maybe around 20-30 % and he was doing fine. Then this morning I woke up and his head was shrunk on the sides and colors were darker. I tested water and seemed to be ok, The ph is 6, He seems to be doing alittle bit better but is not active or hungry. Any advice or input on what the problem could be would be appreciated, I know they can react to water changes but this was the first time this has happened.

