lumens and wattage?

so I'm setting up an NFT system the floor print is 11'x3' and I'm looking for LED lights. I've read that one needs 2,000 lumens per ft[SUP]2. The problem is all the sites selling lights list wattage and not lumens. My question is how many watts will i need per square foot in my grow room?

what i want to do is have these [/SUP]http://www.advancedledlights.com/products/SpectraBoost-Grow-Spotlight-%252d-15w-High-Intensity-LED-Grow-Light.html
4 blue and 3 red alternating, but something tells me this might be too little. Your help would be greatly appreciated.

Lumens are for humans, and are not useful for plants.
For flowering 33 sq ft, you are going to need upwards of 1,000 true LED watts at a minimum, costing maybe $2,000.
But I think that to be truly happy, one needs about 50 true LED watts per sq ft for some serious flower power.

To be truly happy one needs a larger space to grow and scrap the led idea.



You get the most lumens w/ a 600w HID.

RawBudzski said:

To be truly happy one needs a larger space to grow and scrap the led idea.

You get the most lumens w/ a 600w HID.

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While I agree that HID lighting is probably the way to go with such a large space rather than LED, I have to disagree with a few points.

Again, lumens aren't really applicable to LED lighting. Assuming good spectral coverage, as mentioned, you'd want roughly 50 watts of LED lighting per square foot of grow area for optimal lighting.

Next, an 11x3' space ought to be PLENTY large enough to grow all the buds any one person could want, and in fact, it should be enough for more than one person.

In terms of how to light that space, those particular dimensions are long and skinny. To figure out the ideal way to light it requires a little more information on how its going to be used. Are there going to be separate veg and flower areas? Is there a cloning/seed area? If so, those areas could be lit differently.

If the whole thing is for flowering, then one easy way to go might be three 400W HPS lamps, each lighting roughly a 3 x 3.5 foot area.

You could also do a 600W HPS for flowering, 400 for veg, then fluorescents for seedlings/cloning.

LEDs will have more place for larger grows in the future, but for now i think they are best suited to special conditions. One for heat, particularly when the area is already is already hot. Next is small spaces, though a small hps is also suitable. lastly for power usage. I havent tested by my current grow i feel the 170w are doing better than a 150w hps (which would likely pull around 170w as well) but i could be wrong for sure.


If i wanted to light that space i would have 3 bare bulb 400w cmh bulbs hanging with a vert bulb reflector, and then have a 1k or two 600s on a light mover. Its a lot of space for a light mover, but with the 400s it should be decent. Even two light movers with a 600 each would be nice (each covering 5.5 feet)

It can be done with leds, but will cost a ton. If you have a 2-4 grand that you are willing to invest in leds then I can make some serious recommendations. Otherwise, go traditional.

puffenuff said:

It can be done with leds, but will cost a ton. If you have a 2-4 grand that you are willing to invest in leds then I can make some serious recommendations. Otherwise, go traditional.

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That's about right I just finished building a new flowering room and 859w actual draw on a killawatt meter the 2 panels have a combined width of 41" x 20.5" so placing them on light rails over a 6x4 scrog canopy . So covering a 24' square canopy with 850w=35 w per square foot without the light rails so not sure how it will work out but in the past my best results have been with using a light mover and a 400w mh and 400 or 600w hps in conjunction over the same size canopy and had yields around 700-1100grams . So I am hoping I can manage the same with leds but my output for the leds panels plus light movers = $3750 after duty . I will say the leds are among the top 5 most popular led lights for cannabis imho from research but I don't promote for any company but I can say from checking a lot of other sites showing the lights I bought and the journals they were used in final weight always ended up in the .75-1.25g/w rating, and none of the grows were using co2 supplementation like I use. But all in all to build the entire room for these led's , the light rails, a new 12 site ebb and grow system ,new co2 digital ppm controller dual tank co2 regulator fans ,professional wiring etc the entire room cost just a touch over $7500, as I don't scrimp and used rock sol safe and sound insulation to sound proof the room and lined the walls with reflectix over 5/8 drywall all and all the room has a 45 minute burn rating if a fire were to break out. But that was my choice to go all out on proper insulation ,fire rating, esa approved electrical system etc.