I'm running 40 plants under 4000w of hps in a 8x8 space. 11 big 1s under 2k and 30 smaller ones under the other 2k In 1 room right now, quality leds are of course better then single ended hps but your gonna pay for them. I have a friend who can pool 22 zips off of 1 600w timber cob without co2...