We have a 20 long sw tank. My husband and I do not want to go with mh, even though everything I've read on this site says mh are the only way to go. We live in a very small house and do not have central air conditioning, only window units(we rent). The tank is in our bedroom and we don't have a unit in there. We got a great deal on a 4x55 watt Power Compact lighting system ($100 Brand New) We figure this will give us 11 watts per gallon. This will be sufficient to grow things will it not??