I have a 55 gallon with 400 gallons per hour HOB filtration. I have 2 blood parrot cichlids, young, 2-3in, one blue gourami, 2-3in, 6 Odessa barbs. All I want to add is a unique pleco, one that doesn't get over 5inches. If I have room I would add another random loner like my gourami. If I should...