I currently have a 50-gallon tank thats stocked moderately with 1 yellow-tang, 1 pink-spotted goby, 1 purple fire-fish, 1 maroon clown, and 1 scooter blenny. My filtration system is a DIY 15-gallon home-made sump/refug and a CPR BakPak. Does any body think that the CPR would do a decent job taking care of all that bio-load? Does anybody out there run a CPR for their 50-gallon tank?