Aquarium lighting can be installed to enhance the growth of plants, or for simple aesthetics.
Fluorescent tubes are currently the preferable choice, as they generate little heat and do not cause temperature gradients across the aquarium. This type of lighting also consumes the least energy.
Speak to your local aquarist for help selecting a suitable of tube. Some have a specially formulated chemistry to produce a spectrum that promotes plant growth. Others have a ‘flat’ spectrum to pick out the colours of fish, making them appear brighter. Tubes exist that replicate the spectrum of moonlight, encouraging nocturnal species to appear at daytime.
Aquarium grade fluorescent tubes are generally brighter than other domestic tubes. This is to compensate for light absorption in the water.
A fluorescent tube is installed in the lid of the aquarium. The lighting effect is more effective if the light is install at the front, since shadows are cast away from the observer.
Plants need 8 to 10 hours of light a day (the length of a day in the tropics). Any more is likely to cause the growth of water algae.
The installation of a reflector behind the tube can increase the amount of incident light (tin foil can also be used, but I prefer to avoid introducing areas where condensation can gather)