2ft 20W 875 lumen, I already have a few of them. How many of these would I need to grow a couple plants? I'm thinking a grow box roughly 2.5ft wide x 1ft deep x 2.5ft high Hoping 4 or 6 of these lights would be enough?
your gona want at least 2500 lumens per plant, and thats a bare minumum. so just make sure you use enough lights to add up to that, or else your plants won't obtain a sufficient amount of light to grow to their full potential. so you might just need a more powerful light if you cant fit enough weaker lights in your grow box.