1000 to 1200 watts)

120 to 140 watts)

*Assume about 32 watts/sq ft (actual LED wattage) for flowering. Fewer watts might equate to smaller yields while more wattage may lead to larger yields.*

240 to 300 watts)

Different LED grow lights will have different efficiencies. More efficient LED grow lights will use fewer watts to emit the same amount of light that a less efficient LED grow light will exude. Therefore, as mentioned above, wattage is not the most accurate tool to know how powerful of a grow light you need for a particular coverage area.

250 to 300 watts)

500 to 650 watts)

*When we talk about wattage inthis article, we are referring to the wattage drawn at the wall, not what the manufacturer states as “LED wattage” – which is typically the product of the maximum LED wattage and the number of LEDs. For example, 300 x 3-watt diodes would be a 900 watt LED grow light. However, the LED grow light might only draw 500 watts at the wall.*

900 to 1100 watts)

The Ultimate Guide to Help You Choose the Correct Wattage for Your Grow. If you are wondering how many watts of LED power you need for your grow, then read on.

I need to know the recommended lumens per square foot.

the lumen number on a light bulb package refers to its output at a reference point either at the point source or the surface of the bulb

if money is no object they make a new light meter that measures

plant usable light they are called quantum meters they read in a new unit called micro einsteins they start around 200$

for hid lights assume low for about half the lumen number at 18 inches away [ you still might have heat issues at that distance]

i did the light meter and tape measure stuff a while ago so this is based on real measurements although i am not a tech geek grower

to make it simple for CFLs at 3=6 inches away you get about 2/3 – 3/4 the lumen number on the package

there are tables on the web that give conversion for common light sources to micro einsteins

lumens lux and footcandles all measure the intensity of a light source

this output decreases with distance some inverse square ratio

to get a real usable light intensity i use an old fashoned light meter for photography in the incident mode [this is the little

white dome thing — it measures the light actually falling on the point of measurement]

I need to know the recommended lumens per square foot. I read this somewhere on the site but can't seem to find it now. If someone could help me out on…