I do mine 6 to 9 and change 6 to 6 when the DST stops. I just read in another thread that Ray, when he did under lights, did his 14 hours on 10 off all the time.

im going to do reading up on daylength for flowering because i saw that it is more inflenced by temp change than daylength. but who knows. for now im staying safe at 14hours a day since its such a low output on these t12 and theyd prolly benefit the extra light

That's what I heard about the longer duration. I also just heard that most of our orchids come from the tropical zone where day/night is pretty much average at 12/12 !!!

i figured that too since theyre from the equator. maybe even a 16 hour light perios would be cool, and sleep 8 hours like us humans :biggrin: i also wonder what would happen if lights were to be on 24/7

They have to have a night because their respiration changes in the dark.

T8 bulbs will fir a T12 fixture, T5s will not.

Shoot for 6500°K, +/-

Yes, you can bloom vandas under them, but you have to keep them very close to the bulbs.

Yes, you can burn a plant under a cool bulb, if the light flux is high enough.

I just was shopping at Home Depot and they DO carry 2 foot T12's that ARE 6500K but only 1075 lumens.

this is so neat. how exactly do you find the k and lumens. is it on the box? i see that the k should reflect day amount right? it will provide the broadest spectrum. the lumens though i dont get. are they like fcs?

Yes, on the box. K is the wavelength spectrum, and 6500K is the highest in blue and red that plants need. lumens and FC are related, I think 1 Fc is a square foot of lumens, but don't quote me that might be backwards ! I DO KNOW that if you measure you'll read more Fc than lumens from the same spot.

they are t12s. yep!

i grow under 4, 4ft t12s. i have catts and dendrobiums that bloom. i think the secret is giving them as much light as possible in the summer. then its okay with lower light in the winter.

but if its possible for nice high light all year long, that better of course!