I'm using two lights. The side light is a 400watt MH made by HydroFarm. The top light is a 430Watt HPS remote ballast setup also made by HydroFarm and it uses a Eye Hortilux 430watt EN HPS bulb with blue spectrum. So I've got a total of 830watts. I'm also growing in a HydroFarm MegaGarden system, 7.5Gal reservoir and they drink 1 gallon per day which is topped off with just plain water. I'm using full strength bloom nutes 4-8-7 (Floranova series) right now.