Now that I am setting up a 120 instead of a 75 gallon, this is my modified planned stocking list 1. Pair of Ocellaris clowns 2. Cherub Angel 3. Blue Star Leopard Wrasse 4. Yellow Watchman Goby/Pistol Shrimp Pair ( Above are all currently in my 58 gallon) 5. Kole Tang 6. Diamond Goby These 7 fish will bring me about to the 1 inch per 5 gallon rule of thumb ( when sump volume is taken into account). I know this isn't a perfect indicator of what the system can handle, but at least I shouldn't be I overstocked.