how many watts per sq foot ???

I have a 3x3 space and right now I am running 220 watts @ 15000 lumens

My plants are around 1' at 38 days old and getting some nice branching. I would like to veg for a few more weeks or until they reach 2 foot then flip the switch. They are in 3 gallon containers , I would like to move them to 5 gallon containers for a few weeks before flowering.

would 440w @30000 lumens be enough . This would give me about 50w per square foot @3300 lumens

I don't know about lumens but a 400W hps is just perfect for 3X3 space

diet coke said:

I have a 3x3 space and right now I am running 220 watts @ 15000 lumens

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would 440w @30000 lumens be enough . This would give me about 50w per square foot @3300 lumens

Click to expand...

The more light per sq ' the better, as long as heat is not an issue... What kind of lights? HPS/LED/CFL.... It makes a little difference, however, there are millions of varies...
FYI, if all else is equal, the more intense light, the deeper the light goes...less pop corn buds... more hard nugs with added light... Good Luck !!

One of growings oldest sayings is that a 1000W bulb will sufficiently flower a 8 x 8 room. I have a 8 x 8 flower room with a 1000W HPS bulb. If you are smart you will have a ceiling fan and set the light fixture off-center of the room. You will want some space on one side or the other so you can get in there and mother your little darlings. Fill your flower room by first starting in one of the far corners and work out from there. Leave the other far corner open enough for you to fit back there with a water jug. Also, experience has shown me that having the light off-center of the room makes it easier to conceal the bright light from prying eyes. 'Nuff said. BigSteve.

From what i have read and come to believe is that it is the same as the plants which is 100 watts per square foot. So a good base line is 100 watts per square foot per plant. This is the lowest you would want to go but remember more is always better when it comes to how much light. If you can cool it you probably will have much better results when its harvest time.

I'm with Sand4 on this reply. It depends on the equipment. I went from 400w of HID to 160w LED in the same 2' x 3' grow space and achieve the same results at harvest. Five plants grown in 5 gal containers and harvested 3/4 lbs. of bud. See more info on my grow and equip down at the signature.

Good luck!

This is ALL contingent on the type of lamp your using, as spectrums of light have different penetration depths.
E.G CFL v(>) HPS,
Or LED v (>) any HID lighting.

These two links tell the same story:
http://www.concept420.com/how-to-grow-marijuana/marijuana-lighting-guide/




http://www.buydutchseeds.com/growing-guide/light-for-marijuana-indoor




“Ask Ed” says:
http://www.cannabisculture.com/articles/2611.html


More opinion?
http://howtogrowmarijuana.com/HPS-grow-lights


Use what works best for you… so do you agree with the above so-called experts? Or, have you found that “Your way” is the best…


Happy Lighting….

These two links tell the same story:
http://www.concept420.com/how-to-grow-marijuana/marijuana-lighting-guide/




http://www.buydutchseeds.com/growing-guide/light-for-marijuana-indoor




“Ask Ed” says:
http://www.cannabisculture.com/articles/2611.html


More opinion?
http://howtogrowmarijuana.com/HPS-grow-lights


Use what works best for you… so do you agree with the above so-called experts? Or, have you found that “Your way” is the best…


Happy Lighting….

yup good rule of thumb no matter what light type your using is 100w per plant, you can have less then this for veg down to about 50w per plant but for flowering 100w per plant is recommended regardless of light type

Adjorr said:

yup good rule of thumb no matter what light type your using is 100w per plant, you can have less then this for veg down to about 50w per plant but for flowering 100w per plant is recommended regardless of light type

Click to expand...

so this begs the question -- if I have 3 plants in a 4x2 space, and 3 plants in a 4x4 space, 400W would be sufficient for each since the 100W to plant ratio is still achieved? (Despite the larger square footage)

3x3 400w light... in a perfect world you would have a 400w light in a 4x4 room with reflective material and a half foot barrier around the room so the light can go past the plants and bounce back. in a 3x3 room I would stay in a 2x2 fooprint and let the plants fill the room not fill the room with plants, I would also only grow 1 big plant under a 400w light and by big I mean wide with several foot long colas. I like big plants, it just seems better for me trimmed up so there is no bullshit just thick dank colas

yes but I would put the plants as close to each other as possible to make sure there all in the optimal footprint of whatever light type your using. Areas that don't contain plant material do not count towards the square footage you need to cover. A 400w light should cover 4 plants adequately so 3 plants will be fine im sure