Lighting question for a (3-4) plant grow

Waiting on the mail to bring me good news. Working on my room set-up. I’ve got 2- 300W Viparspecta full-spectrum LED grow lights that I’ll mount from the ceiling. The plants are WW autos. I want to add some side lighting and saw some T5 HO 4- 4’ lamp fixtures at a big box store today. They take 54W tube lamps and throw off nearly 18,000 lumens. They were very bright. Thoughts on using them as supplemental side lights?


What size room? I have heard 50w for every 2 square feet. And remember only the top of the leaf absorbs light so dont get your side light to low or below the plant. It will be useless.

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The area is 7’ wide. The ceiling is 8’ high. I can make it as wide as I want.

I would aim more for 50 true watts per sq foot. At least 40w psf.

So if I set up an area that is 5’ wide and 4’ deep, that’s 20 sf x 50 = 1000W. Another 300W fixture will get me close enough.

Im sorry. Im thinking 2sqft per plant. @Matthew420 hes right about the lights sqft. So for 4 plants you need a 4 x 4 area. That would give you 16sqft and you would need 800 watts of light. You need to find out the true wattage of your LEDs. most are half or less true watts compared to advertised wattage.


So the lights are 300W but say they only consume 137W. So is it a 137W or a 300W?

137w is the true wattage. The manufacturers like to compare there lights to HPS bulbs. So what they are saying is that light is comparable to a 300w HPS light. But I would use true wattage for you calculations. So coverage for each light is about 3sqft.

My experience with led’s is that they are somewhere in between the two. I am using led’s exclusively (although I supplement with sun when possible) and I love them. The T5’s for side lights should be fine; just rotate your plants frequently. I would install just as much light overhead as I possibly could and it’s something that you can do a bit at a time as this grow gets larger. I have a 4’ X 6’ X 6’ high box constructed of Styrofoam that now has 3 ea 1,000 watt plus 2 ea 300 watt and side led’s. That’s a lot but I have zero burning and the temperature is completely manageable in a hot garage with 100 cfm exhaust fan.

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So in reading the user instructions (I know, what a concept!) it says the 300W reflector series is best used in an area that is 2’ x 2’. So I should be good with two of them plus additional HO fixture.


Yea you’ll be good with 2 of those LEDs, and the T5s will be great for supplemental lighting! I personally am running 2-300w MarsHydro LEDs, with a 2’ 5-tube HO T5 fixture hanging vertically for supplemental lighting.

This is my 5’x5’ tent, 6.5’ tall


That is exactly how I have my area set up! Thanks for the confirmation that I’m pretty solid in my thinking!

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