I have a 2 1/2 year old red belly that is swimming erratically today. He has not eaten for 2 days as well. This happened one other time (a month ago) and I cleaned the tank and changed 1/3 water. It was fine the next day. I changed a 1/4 of the water today, added dechlor and Ph balance but there is no change so far. I just turned the light off and told him good night. Any guesses what the problem could be? I am getting the water tested tomorrow.