It is a hagen surface skimmer with no additional skimmer attached to a Aqua Clear mini and with an additional powerhead giving the whole tank 270 GPH. The tank is about 3 to 4 months old with a firefish and a ocellaris clownfish. I have a Green Pineapple Brain Coral, a Candycane coral, some GSP, Pumping Zenia and a Colt Coral. I also have 11 pounds of tonga liverock and 15 pounds of crushed coral.