peacock bass!!!!!!!!!!Unless you have 180 for it ready, or a pond, throw it away........The pair of convicts should go into a seperate 20-55g tank right now..............Because once they start producing spawns, you will be askig a lot of questions about breedig and keeping the fry alive.............The tank sounds great for the two oscars for life...............Adding a fancy pleco(maybe pair) will not hurt the system...........A would try a royal pleco..............