i have 2 green terrors, one just about 7 in and the other about 1.5 inches. the 7 in boy is housed in a 75 gallon with a pearsei and common pleco. i have a 55 gallon with a Hi fin spotted pleco. i know i can house the lil one in the 55 g. Is it possibe to have another tank mate? if so what would you recommand?