im searchin and so far the main reply on lightbulb watts is get 150watts, well i went to home depot and found some cfl's they had (1) 150 watt for $10.00 or they had a (4) pack of 100 watts for $10.00. so would the extra 50 watts make that much of a difference? (would it be ok to use the 4 100watt bulbs, instead of 2 150 watt bulbs?)
Those cfl's aren't actually 150 or 100w's, that is the equivalent number to an incandescent (lumens). The 150w's are actually 42w's and the 100w's are probably around 30w's or so. Generally the higher the wattage, the better efficiency as far as lumens per watt. But since they both aren't very high in terms of wattage, then the 100w's should be just as good if not better than the two 150w's.
Yeah, I second what IndicaSativa420 said. Make sure you check the amount of lumens emitted by the bulbs because that's all that really matters.
also remember to check the typo of light,is it daylight, white lite, or warm light. Whtite-blueish is better for veg, a touch of warm light could work better for flowering. How bout getting 2X 150 and then some 2 extra 50 watt to add up to 400 watts However, if going to run a 400 watt system go for an HPS Currently on my first grow 4x39 daylight Osram Fluoros hung up in chains, some old school twist, jeje. 4 Indicas 6 Sativas .5 g/L of "triple 17 plus" (17-17-17 N-P-K and some micrconutes) .5 g/L of "nutriflor" (15-30-15 N-P-K) 35 days 12-12 dont know if my system will live up for my expectations; around here the 400 watt HPS is the most popular system.
Hmmm. Lets see : 2x150= 300W for $20 4x100= 400W for $10 or (your text is ambigous) you own 1x150 already. So : 1x150 = 150 already + 150 = 300W for $10 4x100= 400W for $10 I wonder why you cannot decide between these two options!