The pump is the recomended iwaki 100 rlt. I will send some pics of my system soon. I do run carbon and have for 6 years on the system. I am not running ozone thru it. I let it run for 2 weeks recently without touching it, feeding only pellet food, not feeding the eels. It worked OK, recovering after feeding after several hours. Then I fed the eels and after 3 days without touching it the skimmer never recovered, there were no bubbles in the tower let alone foam. I had to go from the normal full open on the gate valve to about 1/2 closed to bring the bubbles up. Then it started producing nice foam. In the morning the 5 gal drain bucket was overflowing and I had to open the gate back to the normal full open.I am not going to touch it again. I modified the sump and squeezed my old ER skimmer in with the EV2000. As I said, the system had been running for years using two ER skimmers in the sump and they worked great except the Sedra pumps were a lot of trouble. I think the skimmer would be OK for a fish only tank tank that is fed normally. The old ER skimmers kept on cranking no matter what food went in the tank and I have had eels in the system since day one.