Two (weird) newbie questions concerning lighting.
 

Hi, everyone -

We're in the process of planning the lighting needs for the future orchids in a very dark old home. I was discussing some possibilities with my husband, and well, both of us are clueless as to whether they would work or not.

So here they are:

1. After the bathroom is completed, there is a light on one wall above a mirror with a shelf. This wall is bookended by two windows, the only two windows in the room.

http://www.orchidboard.com/community...BATHROOM_1.JPG

We use fluorescent lamps in the house already, but was thinking about making this specific lamp into a plant light for the mini I plan to put under it. Do they make plant lights that would fit a common household fixture? And if they do, would the common household usage of a bathroom light (on and off during the day - mostly off, and on for several hours at night) be enough or harmful (with the off hours) for an orchid? Or should I leave the light on during the day and change out the bulb for night use? (or unscrew it so that it does not come on)
We have an overhead light and will have a three lamp light over the medicine cabinet on the side wall.

2. With the natural way the sun rises, moves across the sky and sets - would it be reasonable for a set up of lighting to mimic the sun's changing intensity during the day? Would the orchids even notice? (If it could be done?)

Thanks!

First thing is what kind of orchids are you trying to grow under lights? Low light orchids like phals & paphs can be grown generally under cheapie shop fluorescent type lights. You can dress them up by placing them inside enclosures if desired. Generally most of us that use lights indoors for orchids just set them on a time and run them 12-16 hours per day.
Generally speaking the bathroom light fixture that you have noted is not going to work well for any orchids - not enough light.
If you only have a couple orchids you could potentially use the highest watt CFL (curly fluo. bulbs sold to replace incandescent bulbs) in a fixture and place your plants VERY CLOSE to the bulb. Ideally the bulb should be in a fixture like a clamp lamp/reflector - so you could direct the majority of the output at the plant, otherwise most of the output will be directed in directions not useful for your plant(s).
Higher light need plants are going to need more expensive supplemental fixtures/tubes - like T5 fluorescents or metal halide/sodium vapor - which also create a bit of heat that is another issue to deal with.
In terms of mimicing the natural daylight/night cycle remember the majority of these plants come from tropical areas where the length of daylight doesn't change all that much over the course of the year. Some of the will experience some seasonality in rainfall or lack thereof and to some degree a temp. change associated with that.
Bottom line - in general, you will need to specifically purchase/direct the output of light towards your plants - don't count on them being able to get enough from normal output used during typical day to day living of household fixtures.

For this specific area, I wanted an mini phal for the shelf that will be placed between the windows.

Yeah, I see what you're saying. there will be a mirror inbetween the light fixture and the shelf I had wanted to place the orchid on. . .so there's no way that particular light would be sufficient. . .must make a different plan, I guess.

This makes so much sense! Thank you!