There is this white blotch on the side, behind the fin on what I would call the tail area on my glasscat. I thought it was fugus so I started treating him with primafix 5 days ago and there is no change in the blotch. So , I think it might be something else. He is in a 20 gal. ph 7 , 0 everything else. I do 50% water changes every wednesday and sometimes do 25% on weekends since there is a pleco in the tank that makes alot of poo. Some live plant, not many and I do not know what they are called. This may be too much info but I am worried about him and need some advice as to what it may be.:help: