i just have a few questions hoping someone can help. wonding what size light should be used in a 5 foot x 5 foot room. 6 foot high. was thinking maybe a 600hps. under the light will be 4 tubs all with 2 plants in each tub. unless someone can convince me that it will be to crampped. also has anyone had any eperience with heat rope's for keeping the growing medium warm? the plants will be in coco-pearl. also i know this is an almost impossiable question to answer. but what have other people's yeilds been from a 600 watt light? just trying to work out if it is worth my while in power to run the 600 watt light.