The more nearly perfect growing conditions are, the faster plants will grow, the healthier they will be, and the more food they will need. That is another way of saying that the plants close to the lights, which are the substitutes for the sun, need more food than plants farther away. Watch for new growth; it is lighter and thinner than the old. If they are growing fast, feed them well. Counting the cost of what it takes to let their beauty shine; priceless.
” Fixtures & Bulbs”
The two types of fluorescent lamp fixtures are the industrial type, which has a built-in reflector, and the strip (channel) type, usually used under shelves or cabinets, with a supporting background painted with flat white paint which acts as a reflector. The industrial type can be hung in the open, raised and lowered with adjustable chains that hook into the fixture; however, it is normally painted with glossy white paint which reflects less light than flat white.
If you choose the industrial type for its flexibility of height, it would be best to remove the glossy enamel with paint remover and repaint it with flat white, in order to get the maximum light reflection. (Use protective glass’s, mask, gloves, also tape the sockets & cord, before painting. Best to paint outside.)
Both fixtures are available in models which hold from one to four tubes and which can take various watt-size lamps. The most readily available replacement bulbs are the 40-watt (48-inch) and 72-watt (96-inch) sizes. The 40 watt size will light a growing area of 48 by 6 inches, and the 72-watt a space of 96 by 6 inches; two bulbs would double the available growing area.
Your next problem is to choose the type of bulb: the preheat lamp, the rapid start lamp and the slim-line instant-start lamp.
If you use your four-foot-size fixture, a preheat lamp starter is good for the sake of economy and good performance in high humidity. The eight-foot fixtures are most often available only in slim-line instant-start types.
Do not assume that two short bulbs will give the same light as one long one–light intensity is reduced at the ends of the tubes and more tubes naturally will have more ends! However, two shorter tubes might give greater flexibility by letting you adjust them to different heights for different growing needs.
Plants must be turned often to prevent their reaching toward the light supply and becoming lopsided.
Care To Plant 