How many lights do i need ???


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Apr 30, 2006
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i have a 150w sunsystem fluoresent that i use when i get my babies started first week.light is great,it doesnt put out alot of heat.

Stoney Bud

Bongo said:
Hello, i would like to build grow room which is 6metre length by 2metre width and using CFL S lights (link below), how many of them will i need ? and will it better to use 125watts or the 200watts?
Based on a 3,000 lumen per/sq ft usage during the vegetative cycle and a 5,000 lumen per/sq ft usage during the flowering cycle, these are the formulas necessary to calculate the light that you'll need.

The CFL's you're thinking of using would create a LOT of heat. For a grow this size, they simply aren't practical. Using only HPS as a cost saving variable, the below calculations are accurate:

6 meters x 2 meters = 19 feet, 8 inches x 6 feet, 7 inches
19.6848 ft x 6.5616 ft = 129.1638 square feet
129.1638 x 3,000 lumens = 387,491.35104 Lumens necessary for vegetative growing
129.1638 x 5,000 lumens = 645,819 Lumens necessary for flowering
One Hortilux 430 watt HPS bulb puts out 58,500 lumens
387491.35104/58500 = 7 bulbs needed for vegetative growth.
645,819/58500 = 11 bulbs needed for flowering.
You'll have a total wattage of 3,010 watts for vegetative growth.
You'll have a total wattage of 4,730 watts for flowering.
That's a lot of wattage. Your electric bill will be staggering.
The electric company may inform the police of your usage.

Stoney Bud

Your welcome man! This whole group is based on everyone helping everyone else in ways that they can. I just happened to know this answer. The next one will probably be someone else. Then, you'll help someone else and we'll have made a complete circle.

Good luck to you man, and let us all know how your project comes out.

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