These can be connected to regular electrical outlets in most cases. These special units are not necessary. Lamps can be purchased alone and fitted into the design of your home, as long as they provide sufficient fight intensity. A photometric light meter will help to determine correct placement of plants in relation to fight sources. The intensity and duration of illumination required vary from plant to plant.
Experimentation is the only sure method to determine the best solution for each plant.
If plants are not receiving enough light, they begin to grow tall and spindly as if stretching towards the light, and foliage becomes pale green. Such plants should be placed nearer the light source, or given a longer exposure period. If too much light is problem, bleaching of leaf and flower color occurs, and may lead to browning and shrivelling. Leaves are small and overly compact, and may curl under at the edges. Too much light inhibits flowering in species such as poinsettias, orchids and chrysanthemums.