Question
I've realized,through trial and error,that the only place I can put my beloved orchids and plants(due to my beloved kids %26 dog)is a spot with insufficient light.So I went ahead and bought a gro-lite that was apparently too strong because now I have burn spots on my Phalaenopsis and Cattleya orchids.My young Cattleya has yellow to brown burnt look on tip of a new leaf, and the Phal has a little yellowing of a couple leaves on one side( I was trying to get it to rebloom by cutting spike below the last flower node and trying to give it the right atmosphere). I was wondering if I should: A)slowly re-introduce them back to a lower wattage gro-lite. B)Keep them shaded for a certain # of days. C)Only use fluorescents.
Probably most important question is how many watts and how far away from the orchids when using fluorescent or incandescent lights?It seems difficult to find the knowledge to accomplish the correct lighting AND placement of lights.-especially when space is an issue and trying to keep the cost at a minimum.
I thank you so much for your time.Your answer will be greatly appreciated!
-Susan  

Answer
Thank you for some good questions Susan.  If you were using a  "spot grolight", those do get pretty hot, so you will need at least 12 inches separation between light and plant and a small fan to dissipate the heat.  I recommend the 4 foot florescent tubes(two shop lights with two 40 watt cool white tubes each is ideal).  They are less convenient because they take up more space and must be hung.  The cool white florescent bulbs are fine and you need not spend $7 plus for the special grow tubes. The only time I have seen leaf burn under these florescents is when a leaf actually comes into contact with a tube for a prolonged time.  You will want to grow the cattleya as close to the tubes as feasible (eg 6 inches for a young plant and closer for more mature plants).  Phalaenopsis can be grown with the same or less light as the young cattleyas. If, because of the space issue, you don't have room for the 4 foot shop lights, you can use clip on lights, but try using the compact white "natural" full spectrum florescent lights to avoid overheating.  Generally, the light spectrum isn't as crucial as the amount of light.  With florescents, which generate less heat, you can grow the plants closer to the light without overheating.

As to cost, the shop lights can be obtained for $10-$15 each, the four foot florescent cool white tubes $1.25 each, so a total investment of less than $40.  A clip on fixture with a 100 watt compact florescent will be half of that or less but will not generate as much light over an 8 square foot area covered by the 2 shop light fixtures.