I have a grow box that 2ft wide 2ft deep and 32in tall. I plan on growing around 5 small plants in it and I have to use cfl's and I was wondering how many watts I should need.
for 5 plants you would need around 300 watts of CFL's. This would be around 12 lights but in a space that small i wouldn't try and grow 5 plants. You will not have good light penetration for the lower areas. I think 2 would be great but at the most 4. With 2 you would have about the best bud though.
As a general rule, you will need at least 2,500 lumens of light per square foot of garden...of the correct wavelength. Chlorophyll Absorption Wavelengths Chlorophyll a 410 - 430 nm = blue 662 nm = red Chlorophyll b 453 nm = blue 642 nm = red
Ok thanks I'll lower to 2. Does anybody have an idea what kind of yield i'd get using 150watt of cfl's on 2 plants that are both about 2ft tall