how many watts per square foot/inch?

[wman44]

im in the first week of flowering my first cabinet scrog and im curious as to what kinda yeild i might expect.
my cabinet is about 35 inches tall 22 inches wide and 15 inches deep (roughly)
i have one plant thats a northern lights mix one from a grab bag that a friend ordered.
i vegged for about 8 weeks and trained the plant quite nicely under a screen that is 13-14 inches from the light which is a 250 hps.last night i quickly counted the branches that are growing through the screen and came up with a total of 55 4 of which are looking exceptionally nice, the internodes are really fuckin close together.
the temp at night time goes down to 65 and during the light period it goes up to 75-77.
im also worried that the plant may get too close to the light but theres so much ventilation that i dunno if i should be too worried about it.
so what do yall think? im not very good at math so i have no idea what my watts per sq ft is...im guessing its close to recommended 50.
will i get enough buds to get me through the next harvest if i smoke about an eight a week?

[wman44]

guesses?
im thinking 2-3 oz..mabye?

[Roughrider]

Think of lumens, not watts. Watts are a measure of power. Different types of bulbs are more efficient, so they use fewer watts to produce the same amount of light. Light production is measured in lumens. You really need at least 2000 lumens per sq. ft. striking your canopy; over 4000 is better. A250w bulb puts out around 25,000 lumens, and you've got an area of 2.3 square feet. I think you've probably got some light overkill; you would probably do plenty well with a 150w HPS in that small of an area and have less problems with heat and stress. Your plants aren't getting all of those 25,000 lumens because your light is farther away...but your light is farther away because of the heat. A 150w bulb would produce less lumes, but you could move it a little closer, which would make up the difference.

But, hey, if it's working, don't change it. Your temps sound good. If the plant looks good at this point, I wouldn't mess with the lighting. Focus on the other stuff; ventilation, temps, humidity, nutes, etc. I can't guess how your yield will be, but it sounds like you've done pretty good with your setup so far. Good luck.

[wman44]

thanks for the reply...it boosted my confidence