closet grow - lookin for advice

Here is my potential setup:

Square footage: 4 +/- (4-5 10" pots)
Height of grow area: 4'-11"
vertical space: 3'-9" (45") (adjusted for pot height (7") and light fixture height (7"))
Light: 150W HPS -OR- 250W MH/HPS

I need some help with what fixture I should go with; I have heard the general rule to apply in determining light wattage is to multiple 40W by each square foot for the minimum light to be used and 60W by each square foot for the maximum. Accordingly:

40W X 4 sq ft= 160 >>> 60W X 4 sq ft= 240

The real factor is that I will only have 45" of vertical growth space; it seems prudent to run the 150HPS, assuming generally that the plants will be around 36"(?) at harvest - dependent upon how early I force them - I will only have 9-10" (?) of separation. I also read that 14-24" is the generally accepted rule for a non-vented fixture, correct?

I also realize that the convertible fixture with a little higher wattage would produce the better harvest but I dont want to overwhelm the plants with light that is too close; BTW, I would love to harvest a ZONE out of each plant but realize my space restrictions may limit that... any thoughts on potential harvest with the 150W?

All this is dependent upon both fixture wattage AND species selection, correct? Anyone who wants to give me some input on the wattage selection with the limited vertical space available growing 4-5 plants in 4 square feet, it would be greatly appreciated.

cheers

If you can keep it cool, you can keep as much wattage as you want in there. I'd say 250w, with cooling, is a good choice.

~ooli~

i have a 400w mh/hps closet grow, 5.5ft x 2ft x 2ft and its hard to cool when the weather is nice out, wen its not my extractor does the business.
just remember airflow is key, just as much as light if not more.

as for strain selection anything indica dominate or pure indica will stay short, i.e White rhino, power kush, aurora indica.

as well 24/7 lighting for veg will keep it short as it wont stretch for light coz it has no dark period

N

L4D said:

i have a 400w mh/hps closet grow, 5.5ft x 2ft x 2ft and its hard to cool when the weather is nice out, wen its not my extractor does the business.
just remember airflow is key, just as much as light if not more.

as for strain selection anything indica dominate or pure indica will stay short, i.e White rhino, power kush, aurora indica.

as well 24/7 lighting for veg will keep it short as it wont stretch for light coz it has no dark period

N

Click to expand...

what kind of spacing do you run between the plants and the fixture? Also, any thoughts on potential yield if I ran the 150W?

My last grow (harvested back in Jan) I did to prove a point, you might want to check it out (Goin Loco, sig link)

I grew this plant to 21 inches tall pulled and ounce and a half off her with 97 watts of light