I have two 5" snake skin gouramis with 7 bala's and 7 silver dollars, 2 paradise gouramis, 2 rubber lip plecos, 2 albino red tailed sharks and 2 rainbow sharks. In a 29 gallon, (I'm soon to be moving them into a 65 gallon) I know it's alot but I've had them for quite a while and I just do alot of partial water changes, all is well. I think the guppys were just too small and tempting to your big gouramis.