How much tablespace can a 4 T8 bulb shoplight cover adequately?
I've read what I can find on light frequencies, shoplight vs growlight, hours per day, etc, etc but can't find info on how lumen output and distance interplay.
"Put the light practically on top of the plants" is what I see over and over for advice, but the lower the light drops the less it "broadcasts" the light out to the sides and the more it just covers an area equal to the light fixture size.
What's the trade off in light output of the fixture vs distance from the plants? If you have four T8s or even four T5, or four Hight Output T5, it seems like you could lift the light a bit higher, cover more table space and grow more plants.
Am I way off base? I just don't know if there are any guidelines to follow beyond "have you light as close to the plants as possible" ?