This is my 180gal reef. equipment used: BS400 sump, K2R calcium reactor, ETS 600 skimmer powered by a Iwaki 30 rlxt, main pump is a Iwaki 40rlt. Lighting: 3x250 watt 65k metal halides, 4x6ft VHO super actinics powered by 2 660 ice cap ballast. this tank was setup using the Berlin method, live rock and sand for Biological filtration. all make up water is ran through a ro/di unit.