theres so musch less cost this way. 600 for the light is not bad cause hydro cuts nutes in half and supposedley 1/3 for aero not to mention cooling cost reduced ventilation in the long run it really adds up lesss bulbs dimmer light, if i enter my G.R. at night i brighten the whole damn block i could go on but you can alreadyu start to see the possibilities the only way thats more efficient would be an outdoor grow where you only pay for soil and water