i had a 42g and i used a corallife aqua pro it was 250w MH w phoenix 14k and 2 compact pc lights it was 380 total i believe. and had luner lights. i really liked this fixture and regret selling it. not that i have a use for it but non the less i liked the fixture it was 24" but would fit up to a 33" tank. i think it kinda expensive but well worth the cash. my tank loved this light, my corals grew extremely well sps and lsp. also it being ontop of my tank my tank would only fluctuate the heat by 1 degree. if i had it to do all over again id get the 38" version for my 90g and run canopy less.. aquatek uses the 46" version on all their SW tanks. they use the 2x 250w MH with the phoenix 14ks and 4 PC lights. Robert.H now has this light and loves it aswell. they also have a 150w version too.