I was planning on building a greenhouse 10x12x8 ( SF bay area) for this up coming winter. I know during winter time, ill have about 11 hours of light. I was thinking of supplementing the green house with LED lights to keep my plants in veg for 6 hours. What is the minimum wattage I need to keep my plants in Veg? does it even matter? I want to use the least amount of light, I just need my plants to stay in veg and not flower. Thanks for any help.