Growing Lights - How many?

[butterfly_muse]

Originally Posted by Bill U.

It kind of depends on what kind of space you have. Right now I grow a majority of my orchids under 25w CFL bulbs that are 6500K light temperature. I have two of these bulbs to cover my small growing space. For the phals- the are arranged about 1-1.5 feet away from the bulb (in a clamp spotlight reflector bought for $8 from Home Depot). Obviously, the higher the light requirements, the closer you can be. I would measure the light that they are getting now and try to match it in the new environment. I have been able to successfully grow/bloom roses and other full sun plants under these lights. So I think that this could be a starting point for your light setup...

How can I measure the light that they are under now? It varies a lot (today we had thunderstorms and sunshine...yesterday it rained all day, the day before that it was sunny and hot outside, etc). Right now I've got my plants on a baker's rack next to the window. I was planning on either keeping them on that or building a shelf as an extension of the sill and then suspending the lights over them. I haven't gotten it all worked out yet, just because we're not in the apartment. I can't do a lot because it is an apartment, so I can't go all commercial grower with giant lights and so forth, lol. How many lights do you have per how many orchids? Right now I only have phals, and I am trying to research but can only seem to get footcandle measurements and converting it to watts doesn't seem to be the correct kind of math (I suck at math, though, so)..