sorry I am new to fish keeping and dove in with both feet which I am now learning was bad. he was in a 29 gallon freshwater tank 1 week old. His mates are 5 neon tetra, 1 banjo cat, 1 rafeal cat, 1 synodo cat, 2 blue rams, 2 platys, 1 pleco, 1 panda cat, 2 angels. all are equivalent to his size. filter is the wheel style for a 30 gal that cycles the water at 150 gal per hour. 2 live plants and 3 decorations. Been battling ammonia with a spike between 1-2 but currently is 0. did about a 15% change yesterday when I noticed he wasn't well. All other fish seem extremely active and happy.