Since they will get some sun, I would go with fluorescent. Now here's the hard part. There are T12, T8 and T5 and there is also a T5HO and a T5VHO. This list goes from cheap to very expensive. T12 will do if they are close to the plants. T8 can be a little further from the plants and so on. T5VHO can be hung on the ceiling and the plants on the floor. You can buy chains for the T12s or T8s so that you can adjust for growth. There are many combinations you can do with this and I don't know what you want to spend. Just something functional or if you want looking like a piece of art. Do you want to hang shelves or use a grow rack or are they just going on the floor?

Taz6122, thanks for the info you provided. I definately don't want to sink alot of money into this, but I do want to do it right. The Orchids will be placed on shelves from refrigeration units. This is all in my basement and definately no plans on creating a work of art. The orchids will be moved upstairs when the orchids are in bloom. The racks will be raised off the floor in graduated steps. I am definately interested in the lighting being on chains so that they can be adjusted. Will shop lights works for this? If so then what type of florescent tubes should I use? Thanks A Million for any additional info you can give me. Hopefully someday I can return the favor, Thanks, Bill

Hi, I just returned to this forum after a 4 year absence...long story. I grew orchids under lights in my basement a few years ago and used the power-twist florescent lights. I was able to flower catts, but mostly grew phals and cyps. Perhaps you should Google "power-twist florescent lights" and read up on them.

Bill shop lights will work and you can get double T12s for about $9.50 ea. The bulbs I would get are around $25 for 10. Get 5000k-6500k bulbs and get some cheap chain to hang the fixtures. Lowes or home depot would be the places to find everything you need. A one stop shop if you will.
Best regards John

I forgot to mention to get the 40w because the 32w don't put out the lumens needed and are over priced. I'll never understand that idea "Save energy by using 32w bulbs". What they don't tell you is you would have to add fixtures to get the same amount of light and that's not saving anything.

The area that I am converting to my orchid nursery is about 10 x 10 feet. The walls are white and there is a double sliding door facing due East. There are no obstructions to block the natural light

Can you afford an extra 384 KWh on your monthly electric bill? If so, then use two 400 watt Ceramic Metal Halide (CMW) bulbs mounted near the center of the ceiling. If the ceiling is painted white, don't use reflectors. It would probably be better to cover your sliding door with an aluminized mylar sheet.

The only reason that I am recommending CMH over High Pressure Sodium (HPS) is that plants grown under HPS easily sunburn when moved outdoors. However, you can use HPS bulbs and then, two weeks before moving the plants outdoors, switch to retrofit Metal Halide bulbs to condition the plants so they won't sunburn outdoors.

These bulbs require ballasts.