I currently have 2 14" oscars in my tank along with a 8" Green severum a 8"Jack Dempsey and 2 silver dollars, they have all been in the tank for well over a year. I have not had any problems with them fighting all. the tank is filtered with a rena xp3 and a fluval FX5. The tank is also not cluttered with decorations either just a piece of driftwood as i cannot find a way to keep plastic plants clean. If it is overstocked should i keep it the way it is or look to trade some fish in for some store credit this spring?