Light is essential factor in aquarium set up. Plant growing needs energy from artificial light source to convert food into oxygen. For this process to complete their is need of adequate light, if not plants will die and decay.

Lighting deserves careful attention not only for the added aesthetic pleasure it may give, but because fishes need it and it is essential to plant growth. The total amount of light required is a matter of trial and error and how much of it will turn the water green while too little stunts plant growth.

The lighting may be artificial or natural daylight. When using the later, the best position is near a north-facing window. This should provide the ideal amount of indirect light, which can be supplemented by artificial lighting, if necessary. This additional lighting should be housed in a hood placed above the tank and may be switched on for three to four hours in the evening.

If there is little or no natural daylight, the lights should be left on for approximately 10 to 12 hours per day. If the water goes green, you must cut down either the natural light or the artificial light. Aquarium; lighting is usually achieved using either small bulbs of 15-25 watts that can be mounted in miniature fittings or fluorescent tubes that come in a number of different colour tints from the pinkish Grolux to the whitish North Light.

A rough guide to the amount of light required for an average aquarium (40-50cm high) with a conventional selection of natural plants is 2-3 watts for every dm2 of be in the tank or 15-20w lights per square foot area.

To avoid high temperatures associated with fluorescent ballast near the water, the apparatus should be installed behind or underneath the aquarium. Note, however, that an important safety precaution to prevent splashing is to have a transparent barrier between the lighting and the aquarium.