We fought hair algea and high nitrates and phosphates the whole time we have had a reef tank...about 5yrs. We feed heavily and i like the lights on, want to be able to see everything when i look at the tank and those are not something i wanted to sacrifice to lower the nutrients. Came across the ats, we chose the waterfall one, researched and built one. Tank is 109 gal, custom built with 20gal sump. Screen is 8" x 6". Cant remember the name of the pump but it is rated at 800gph. Lights are led hydroponic grow lights mounted in a 8.5" clamp light, one on each side..will attach a pic of the bulbs...paid about $60 for everything and built it in about 1/2hr and building things is not my talent. Got it running, has been running about 6wks now and hair algea is gone, parameters are perfect, we got one sps coral which isnthriving, before the ats couldnt keep one alive. We run it from 6p to noon. We grow algea like pros lol and have a great pod factory. There is a site, algaescrubbers.net that is dedicated to building and using them and they were all very helpful about walking us through the set up etc. We will never have a tank without one again, i cannot say enough about how incredibly well this thing has worked. Attached pics of ours right after we built it and the bulbs we are using. I know this isnt a reactor but wanted to share our experience with the ats. I imagine anything that does something similar, grows algea in a controlled fashion, would have the same benefits.