I see a lot of questions on what light to purchase, so I thought I'd tell you how my orchidarium is doing a little over a year after splurging on this. In a word - amazing! This thing is super bright - do NOT look into it!! Prior to this, I had two or three of those octopus style plant lights that go for about $15 each. After installing this, I immediately saw new growth on a lot of my plants.
When I first set it up, I stacked 3 pieces of 2x4's up to let the plants adjust a bit first. I removed on block, but have left it on the remaining two pieces, leaving at about 8" from the top of my setup since it is pretty bright.
My
Ascocentrum (Dyakia) hendersonianium is right at the top of my tank and is currently putting on a lovely flower display. Some others near the top, like the mini catts, are pretty dark purple, but not actually burnt. My
Neofinetia falcata kishu ryofuku is one of the lowest orchids, about 40" down from the base of the light. It is also shaded by some plants from above, because I heard lower light would cause greenish blooms, which it did get have last month. (I post in the Miniature Show & Tell section regularly if you want to see what else has bloomed).
The bottom of the tank is 47" from the light. It has sphagnum moss, some other mosses, several volunteer maiden hair ferns, and random fern my husband brought home from Florida all growing well.
Mt orchidarium is about 40"W x 21"D x 48" deep, and the light fits it perfectly. While I have 65+ miniatures growing under this, it probably isn't going to be the best choice if you have "regular" sized orchids spread across a wide area.
Overall, money very well spent. I can really see results with this light.
Amazon.com