I have a 125 (6ft) tank with (2) 4" tiger oscars, (1) 6" male red shoulder severum, (6) silver dollars (baseball size) .... my question is can I add a satanoperca leucosticta .... and what about a pleco maybe? I would like some sort of bottom scavenger. I have (2) AC500 and (2) 405 Fluvals for filtration and do weekly 50 water changes.... am I overcrowding too much?