Alright so i have these 26watt 1700 lumen cfl's , does 1700 lumens mean perbulb or in general? I've read somewhere that you need 2000 lumens to grow.
Per bulb... but the light from a CFL diminishes very quickly so to get that output the light has to be right over the area you're illuminating and then it is not a very wide coverage area. So you will need at least three spiral CFLs per plant and twice that wattage (per bulb) for strong, healthy growth. Peace
Way more. noober's got it, you can use lower wattage daylight bulbs to veg with, but come flower time you want as many 42w bulbs as you can fit. Wal Mart's got em.
rule is 2800 per square foot of grow space, if a foots under or actually is a foot square, then thats the rule.