To start a new crop, it is best to begin with a fresh soil. This is especially true if the plants were in small pots or were root-bound.

If you have fertilised regularly, the soil may contain near-toxic amounts of salts. Most of the salts build up in the top two-inch layer of soil. To salvage large quantities of soil, discard the top three-inch layer of soil from each pot. Add fresh soil and bulk fertilisers. Thoroughly mix and repot in clean containers.

It is generally not advisable to use the same soil for more than two crops. Although the used soil may not support healthy growth for potted plants, it is an excellent addition to any garden soil. Spread the soil as you would a mulch. The salt concentration is quickly diluted and benefits, rather than harms, garden soil.

Periodically clean the tubes and reflectors to remove dust and grime. As with windows, this dirt substantially decreases the amount of light the plants receive. Fluorescents lose approximately 20 to 40 percent of their original output within a year's use. Generally the higher-wattage tubes decline more rapidly than standard-output tubes. Vita-lite tubes last the longest, followed by standard fluorescents. Gro-tubes are the shortest-lived, and most growers replace them after two crops. Older tubes can be used to start seedlings and during the first month of growth. Since the plants are small and the light system is low, the old tubes generate enough light for healthy growth. Replace incandescent bulbs after 500 light hours.