Is 100w per sq ft too much?

[CanGroIt]

I'm about to build a 4'x2.5'x7' (Width x Depth x Height) grow cab and will have 100w per sq ft for flowering. Has anyone else had any experience with this much light per sq ft? If so, what kind of yield can I expect with this much light or is it overkill?

CanGroIt Reviewed by CanGroIt on 02-09-2011. Is 100w per sq ft too much? I'm about to build a 4'x2.5'x7' (Width x Depth x Height) grow cab and will have 100w per sq ft for flowering. Has anyone else had any experience with this much light per sq ft? If so, what kind of yield can I expect with this much light or is it overkill? Rating: 5

[canniwhatsis]

Lets see, I've got 1000w total (400w +600w) spread over a 4x9 room (36sq ft) works out to 27.7777 watts per foot, and that's PLENTY of light for some awesome pulls.

My old flowering area was 4x2.75 or so, had just the 400w over it. THIS grow only took up 1/2 of the space

I have heard of "light bleaching" where a grower is using too much light, but I've got no clue what the threshold is for that.


1000w in that little of a cabinet is gonna make for some SERIOUS heat issues BTW

[Dexter007]

calculate 100 watts to he lumens or par wats an you will see..
and 1000w for a small box or wardrobe shouldn be to big of a issue if your using cooltubes...just to keep tempeture and moisture level right gonna be a bit tricky


NB(IV no experts just plenty of reading and experience working with my growing mates)

[CanGroIt]

I too think that I will have to battle the temps and humidity.

As far as the temps go, I live in an are where day time temps usually stay around 70 degrees year round. I plan on running the flower box from 9pm - 9am. I have a six inch inline blower I'll connect to the air cooled hood to suck air from the cab space through the hood, through the fan, through a carbon filter and out the cab. So hopefully the mix of outside night time temp air and the blower will be enough to keep the temp down.

And for humidity, I'm going to have to do some research to come up with a slick method to dial that in.

For nutes I'm using Bio Bizz products. B1, Fish-Mix, Alga-Mic, Bio-Bloom, Top Max. And Kool Bloom from GH. Will be using six inch pots and doing SCROG method. I did some more calculating today and found that if I extend the box to 2'8" instead of 2'6" I can fit 7 more pots. So I figure I can fit 34 ladies in there. It will be tight but I will be trimming. Going to do rotating harvests with this cab so I will have 17 of them ready for harvest every month.

Ok so I have experienced bleaching before. I had a 2' x 3' x 6' cab with one plant in an aeroponic system. Had the 1k on that cab and it wasn't until about the 7th week of 12/12 that I noticed the highest cola starting to bleach. It was about 18" or so from the light so I simply bent it over and it kept growing fine. Yielded between 3-4oz of that one plant from that trial.

I really hope the concentration of light does more good than harm. I don't really have a choice with grow space right now so I have to utilize what I can, for now. And since I only have two 1k lamps, I have no choice but to use one. I wish I had the space to use them both again but i don't, not yet anyway.............