I started out growing orchids on windowsills supplementing ambient light with 4' two bulb fluorescent grow lights. Later it became necessary to build a light stand to accommodate my burgeoning collection. This is a three tier light stand with (2) 4' two bulb shoplights on each level. The shelf dimensions are 2'x4' and are height-adjustable. When growing under fluorescents, mix different bulb types for better spectrum, keep bulbs as close to tops of plants as possible without burning and aim for about 15 Watts of bulb per square foot of growing area.
As your collection grows, one of the challenges is how to get water and fertilizer to all the plants with the least effort. One simple solution is a reservoir with a sump pump connected to a garden hose and watering wand. With this setup, I can reach anywhere in my basement. As long as the sump pump remains immersed, its OK to leave the motor running while the valve on the watering wand is closed.
A primary goal under artificial lights is to reproduce the intensity and color spectrum that your plants need. I am sold on these new combination lights that place High Pressure Sodium lamps for the red end of the spectrum and Metal Halide for the blue end, both in the same fixture. They are available in 500, 800 and 1000 Watt configurations. For my 11'x 6' grow area the 500 Watt system hung about 3' above the plants is perfect for Paphs, Phrags and Phals.
A drawback of HID (High Intensity Discharge) lighting is that is is a point source. One way to compensate is to use a light mover. This 6' motorized track shuttles the light from one end to the other in 20 min. and then back again. This provides a more even distribution of the light along the length of my grow room and eliminates "hot spots."
The floor and concrete walls of the grow room are sealed with white waterproofing paint. The ceiling and 2x4 constructed walls are sealed with two layers of 4 mil poly which is covered with reflective white melamine sheeting
view to left
view to right
The bench, designed like a shallow box, is made of pressure treated lumber painted with waterproofing paint and lined with two layers of 4 mil poly. Plants are placed on white plastic eggcrate supported on lengths of PVC pipe laid in the bottom of the bench. This provides excellent drainage and air circulation around the pots.
The bench drains into a gutter which is plumbed into the house drain pipe. Good air circulation is of chief importance. Given proper humidity, you can't have too many fans.
Due to transpiration from the plants and the residual water standing under the bench, all my supplemental humidity requirements are met using a standard cool mist vaporizer from the local pharmacy for about $20. It is run by a 24 hr timer set to come on for 15 minutes every hour during "daylight" and thereby maintains constant 80-85% humidity. It holds one gallon and requires refilling only once per week.
When growing in a confined area, plants need fresh air. I installed a vent in the top of my grow room and ducted the stale air out of the house assisted by a continuous duty in-line squirrel cage fan which is connected to a motor speed controller. Fresh air is drawn in under the door. I turn down the speed of the fan so the air exchange rate gives me exactly the humidity level I want. An additional benefit is that this creates negative pressure in the room making it impossible for humidity to escape into the house. The direction of air flow through any leaks is into the room.
One often neglected cultural requirement is water quality. Water of excellent purity can be obtained by several methods including Reverse Osmosis (RO), but the cheapest way is to simply collect rain water. Between 10-25% tap water should be mixed back into pure water to provide required micronutrients.
