Keep them as close as you can to the light without burning. How close that is depends on the intensity of the light/heat, how many fans you have blowing over the tops, whether you have a cooltube or not, etc. There's no quick answer that's applicable to all situations. Put your hand where the plants are. If it feels uncomfortably warm, it's too close. If it's actually hot, it's way too close.

Number of plants doesn't have much to do with yield. One big plant CAN yield a couple of pounds, but you won't grow a plant like that indoors. A more realistic gauge of yield indoors is to aim for half a gram per watt of light, which would give you about a pound with a 1k light. You could theoretically do better than that, and approach a gram per watt, but if you COUNT on that, you're likely to be disappointed.

Here's a pic with some good-sized bushes. Indoors, these are about as big as *I'd* ever wanna see. They're about 4 feet tall if you count the height of the pots.
jamstigator Reviewed by jamstigator on . 4-5 foot plant ok when would i have to start flowering a plan to get it to 4 feet ? and roughly how much of a yield do you think a 4 foot plant will yield? with 5 under 1 1000 watter im hearing i can get about a half pound or a pound of that? Rating: 5