I have a 125 gallon with a 4 inch oscar, a 4 inch chocolate cichlid, and a 6 inch Synodontis eupterus catfish. I have been told I could add up to 2 more large growing cichlids such as blue acara, severum, etc. as well as 2-3 dither fish like Silver dollars, tinfoil barbs, flag fish. What is your opinion? would this be overstocking? I do weekly water changes of at least 30% and I have two filters on the tank. I don't know if that makes much of a difference. I have had some minor chasing and nipping between the oscar and the chocolate - actually the chocolate seems to be the dominant one - but otherwise no problems so far.