How about using 150 watt
hps lights instead of 4 tube, 4 foot
fluorescent lights? I use a Sun Systems 315 watt LEC for the grow area, and I am thinking about adding several Sun Systems 150 watt HPS lights. Those 150 watt HPS lights are less than $60 each, cheaper than a 4 foot, 4 tube fluorescent light. I have 4' x 2' metal shelves, and I was thinking of installing one 150 watt HPS above each shelve.