One 3 ft Sunblaster T5 HO 6500k light w/ reflecto enough for a 3ftx2ftx2ft grow tent?

[InsectMan]

I was reading around on the forums but haven't really found anything talking about just using one light. I currently only am able to get one light fixture so I'll be going with the Sunblaster T5 HO 6500k light fixture w/ reflector. I'll be using this in my grow tent that's surrounded by mylar to optimize the amount of light available for the plants along with the reflector. I'll be able to adjust how the far the light is from the plants as well. If it helps, I'm looking to grow mainly Drosea with some Drosophyllum, Pinguicula, Utricularia and a VFT or two.

Do you think this will be enough?

 

[naoki]

It will be very low amount of light if you want to cover 3'x2' floor. 1x 39W T5HO gives a bit over 3000lumen. Under a simple calculation, you'll get at most 3000/(3x2) = 500fc. That is enough for low light orchids, but not for the high light plants like what you intend to grow. And there is quite a bit of reflective loss, so not all light will be delivered. But if you put the light close to the plants (i.e., lower coverage area, and not utilizing the entire space in the grow tent), it will work well. With 1 bulb of T5HO, you'll be getting around 500-600fc (about 70 micromol/m^2/s of PPFD) at 12" in the middle, so you want to keep it closer than that. If you shorten the distance by half, you'll get about 4x the light (in reality, lower than this inverse square law).