Which 90 Watt LED do I choose

[soul]

Hi all, I am setting up a very small stealth cabinet. The exterior size of the space is 23" wide 28" deep and 30" high. Once the light traps and filters are installed there will be just under 4 square foot of floor space with an obvious height limitation I'll work with using LST

I would like to use a 90 watt LED (supplemented by a CFL in each corner) as it seems the larger wattage LED's are likely to burn the plants in the tight space

I am only looking at the 420 sponsors lights but even there differences appear. Such as 2 band red/blue versus 4 band.

I can't afford 2 lights so I need one to do the job in both flowering and vegetative growth. Based on what I've read both the 4 and 2 band lights should both do this. However, the price differences from $299 - $149 among the sponsors lights make me wonder if there is a true difference between them.

Specifically i'm looking at the dormgrowlights.com red/blue 90 watt led for $149.

Any thoughts or suggestions?

PS. I have the ventilation, odor control and electrical worked out and will post more info in the grow room design forum once i get the lights planned out.
Thanks,
Soul

 

[luckiestman13]

Why so small? Why bother?

 

[soul]

That was helpful.

Why that size? because the CFL PC grow box i'm using is much smaller and I want to expand, plus it fits the allocated space I have.
Why bother? because it will provide all i need and I like challenges.

I'm looking to optimize the space not change the conditions.

Thanks ahead of time for any helpful comments.

 

[luckiestman13]

To me it doesn't make sense. I was assuming that you were growing illegally which is never a good way to go about it plus you won't yield very much.

 

[JJ Bones]

If your not going to grow the plants very tall, I'd stick with the CFL's as LED CAN burn plants.

 

[soul]

Thanks for responding JJ, I knew that was an issue with the higher power LED's but was hoping the 90 watt lights would be less of a problem. I was planning on keeping them at 1.5 feet but that still wouldn't give me much room between the plant tops and the light. If the smaller LED's can't get within 4" of the plant top then I'll have to stick with CFL's

 

[ledtron]

Hey soul, i have been using a two band 90 watt ufo in my phototron for 2 years now. I have never had one get burned and they get real close to the light-- i have 1 right now that is a half inch from the light. LED'S make very sugary buds too--enjoy the grow

 

[soul]

Thanks ledtron that's exactly what I was hoping to hear.

 

[Jozo-sha]

Hi all, I am setting up a very small stealth cabinet. The exterior size of the space is 23" wide 28" deep and 30" high. Once the light traps and filters are installed there will be just under 4 square foot of floor space with an obvious height limitation I'll work with using LST

I would like to use a 90 watt LED (supplemented by a CFL in each corner) as it seems the larger wattage LED's are likely to burn the plants in the tight space

I am only looking at the 420 sponsors lights but even there differences appear. Such as 2 band red/blue versus 4 band.

I can't afford 2 lights so I need one to do the job in both flowering and vegetative growth. Based on what I've read both the 4 and 2 band lights should both do this. However, the price differences from $299 - $149 among the sponsors lights make me wonder if there is a true difference between them.

Specifically i'm looking at the dormgrowlights.com red/blue 90 watt led for $149.

Any thoughts or suggestions?

PS. I have the ventilation, odor control and electrical worked out and will post more info in the grow room design forum once i get the lights planned out.
Thanks,
Soul

Heya Soul, as one of the several LED Evangelists here at 420, I'd recommend reading stevehman's most excellent LED Buyer's Guide for starters. I've not seen spectacular results from the 'UFO' style lights, though that's not to say it isn't possible - they just seem to be lacking in proper wattage or something that limits yields and coverage.

Larger wattage LEDs aren't going to burn a plant, however they will bleach buds if you have them too close to the bud tips; the newer models you find are quite powerful (I will flower mine at around 12-18" above the tops).

My honest recommendation? If you can afford to, get at least 180W of LEDs in there, if you can't and need to really supplement with CFL's, make sure your ventilation/cooling is up to snuff. As far as 'bands': 2 bands means two LEDs with two different spectra. 4 bands means 4 different color LEDs, etc.. Some LED folks like the idea of targeting just the primary photosynthetic response peaks of the plant's chlorophyll a and b (4 band/6 band), others think that certain carotenoids and other products in the leaf require illumination too, hence your 12-20 band lights you sometimes see.

I'm a KISS guy, so I tend to go with 4-6 band lights. I hope this helped, and good luck.

 

[soul]

Hey Joza-sha,

I've read it, I've read as many of the led grow journals and led articles I can find. I definitely agree that a 180 watt light set up would be better.

However with only 30" of height allowing 8" for growing medium. (I'm using soil as I'm very familiar with that and it is more forgiving of mistakes lol) I only have 22" minus the area the light takes up if I give up 12" of space as a buffer zone to prevent bleaching I can only grow to 8" in final flowering.

I'm building with the current intention of using 16 cfl's but it seems that replacing the center 6 cfl's with a 90 watt LED would be beneficial. That is what I'm really trying to decide.

I also have 4 cfl in each corner attached at the floor on 10" flex hose allowing me to move them close to the growing plants on the sides.

Everything I've read says using LED's would give greater penetration and stop the stretching I'm dealing with but I simply don't have the space to allow for anything stronger than a 90 watt. As long as the 90 watt doesn't cause bleaching within a few inches.

If a 90 watt LED will give me a 15-25% increase in yield it will be well worth the cost.

As far as ventilation in my approximately 8 cubic foot box my exhaust system moves 80 cfm. Drawing that through a charcoal filter.