i have one, it is no smaller than eleven inches and i feed it tetra cichlid sticks by hand and blood worms in a lift tube so only the bgk gets it otherwise the others in the tank get it. I put a 14 inch long piece of 4 inch wide pvc pipe with a third of the pvc cut off lengthwise and lean it up against the front of the tank with rocks behind so it dosen't move and i see my favorite fish all the time. how about those 2 bgk's together in pwmin tank. love it