need lighting help please

Tranceus

Active Member
im growing in a 9 longx4 widex 6.5 tall space. so with 36 sq feet how much light am i gonna need for optimal growth? i was think two 400w on each side with a 150w in the middle and some dual 4ft 40w tube flouros all along the walls hanging vertically for supplement light. btw im gonna use all air hoods so i can keep my lights close as possible. any imput on lighting is appreciated thanks.
 

ScoobyDoobyDoo

Well-Known Member
if you want to grow in the entire space then 2 600w lights would be best. a 600w light has a footprint of 4x4. you can stretch it a little when you stick 2 of them side by side. so with 2 of them placed 2' from either end (2' from center of the bulb) they will be about 5' apart in the middle. then i would use the 4' fluoro tubes on the walls at a height halfway down your final plant height.
 

thc&me

Active Member
The way I see it you have 3 optimal choices. You could run 2 x 1000W, 2 x 600W with supplemental CFL or 3 X 400W. I actually prefer to run supplemental lighting with my HID setups as it allows me to configure a more diverse color spectrum for the plants.
 

Tranceus

Active Member
im not growing the entire space. im saving 9 sq ft which is pretty much a 1ft strip of space all the way down the edge of my room so i can have a little room to work in my garden. so 2 400s with the 150 in the middle and 6 4ft dual flouros wouldent be enough?
if you want to grow in the entire space then 2 600w lights would be best. a 600w light has a footprint of 4x4. you can stretch it a little when you stick 2 of them side by side. so with 2 of them placed 2' from either end (2' from center of the bulb) they will be about 5' apart in the middle. then i would use the 4' fluoro tubes on the walls at a height halfway down your final plant height.
 

ScoobyDoobyDoo

Well-Known Member
im not growing the entire space. im saving 9 sq ft which is pretty much a 1ft strip of space all the way down the edge of my room so i can have a little room to work in my garden. so 2 400s with the 150 in the middle and 6 4ft dual flouros wouldent be enough?
no. 400w lights have a footprint of 3x3 under maximum conditions. so basically in the middle you are trying to cover a 3x3 space with a 150w light. the fluoros are great for side lighting but they have no penetration. it might work if youa re growing SOG or really short plants. anything over 3' plants and none of those lights have enough penetration. you've be better off with 3 400's or 2 600's in my opinion. the fluoros would just be for supplemental mixed spectrum lighting.
 

Tranceus

Active Member
yeah i was planning on doing a sog grow i should have mentioned that but im definately gonna take your advice. i did the math on it and the two 400w lights give me 35 w per square ft along with the 150 which is barely above the minimal requirement from what i have read but id really like to have the optimal 50w per square ft i just gotta get through this first grow so ill have the damn money to upgrade.
no. 400w lights have a footprint of 3x3 under maximum conditions. so basically in the middle you are trying to cover a 3x3 space with a 150w light. the fluoros are great for side lighting but they have no penetration. it might work if youa re growing SOG or really short plants. anything over 3' plants and none of those lights have enough penetration. you've be better off with 3 400's or 2 600's in my opinion. the fluoros would just be for supplemental mixed spectrum lighting.
 
Hi all, thought i would put my first post here, 2 x 600w must be plenty for this space.
Light Coverage really depends on the number of plants and in these calculations that data is missing, even knowing SOG is your approach says little really.
One thing people often say is look to get a gram per watt, good starting point but why aim low. personally i have always strived for 1000g per sq metre, in your room thats just under 3000g i think at 2.97sqm. Rubbish at maths me.
Thats quite a bit more than a gram a watt, but shows the difference between one persons idea of what SOG is and anothers. I would have over 100 plants in that space using my own versions of common techniques.
Honestly, how does that sound?
 

newb weed grower

Active Member
afghaniman i like ur style no dought in ur setup ud be using a co2 pump as well
u know i look at what u said two ways one way i agree
first i think over shooting urself is good in a way cause it gives u goals
and i think undershooting it is good cause u cant really fail if u aim low so ull be happy no matter what
 

ScoobyDoobyDoo

Well-Known Member
Hi all, thought i would put my first post here, 2 x 600w must be plenty for this space.
Light Coverage really depends on the number of plants and in these calculations that data is missing, even knowing SOG is your approach says little really.
One thing people often say is look to get a gram per watt, good starting point but why aim low. personally i have always strived for 1000g per sq metre, in your room thats just under 3000g i think at 2.97sqm. Rubbish at maths me.
Thats quite a bit more than a gram a watt, but shows the difference between one persons idea of what SOG is and anothers. I would have over 100 plants in that space using my own versions of common techniques.
Honestly, how does that sound?
there are some questionable numbers in your theory.

light coverage is a constant and not a variable. a 600w or 1000w light will have a constant footprint with only slight variables based on hood size, bulb manufacturer, bulb age, and distance from plant canopy. the actual footprint of the light will not depend at all on how many plants are under it. you are working backward in my opinion. ideally you want to optimize the plants under your lighting footprint. so, for a 600w light you would want to try and keep your plant canopy within the roughly 4x4 optimal footprint the light casts. by optimal, i mean the footprint in which the plants are all receiving between 5000 and 10,000fc. plants in the center can receive slightly higher amounts and that's why it's always good to rotate your plants.

you state that your "goal" is 1000g per square meter. i don't even see how this is possible unless you are doing a vertical stadium or colisseum grow and even then it really doesn't apply. but sticking to horizonta; lighting for now. 1000g is approximately 2.2lbs. a square meter is 10.8sq.ft. so you claim to be able to pull 2lbs 3oz out of an area roughly 3'3" x 3'3"? normally i would light a a grow area of that size with a 400w light. but for arguments sake let's say you light it with a 600w light. even then you are talking about pulling 1.7gpw. that in my opinion is not possible on a horizontal lighting setup. if you can pull those yields on a horizontal lighting setup then please share because i need to learn from you.
 

Dutchmast3r

Active Member
idk why u guys are talking about 3x400w would not be the same as 2x600w...600w lights have better penetration. adding more 400w will widen the footprint but not deepen the penetration..soo it depends on how tall ur growing ur plants..like dude up top said anything over 3ft is gunna need a 600w or better..good luck
 
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