Fish will not thrive in captivity unless we are able to replicate, as closely as possible, the conditions they enjoy in nature. Fortunately for us, the aquarium manufacturing industry has risen to the challenge admirably providing reliable, efficient equipment for the task in hand.
Lighting is essential as it stimulates all life and, of course, we want to be able to see into the aquarium. The usual light source for aquariums is fluorescent tube. Although traditional tungsten lamps (now thought outdated and inefficient) still work and have their adherents, they produce too much heat within the aquarium hood which, in turn, often shortens the life of such lamps.
The lighting fitted ‘as standard’ is adequate for fish-watching but an increase in light intensity will be needed for better plant growth in freshwater tanks and coral growth in marine aquariums. Fit more tubes, if there is room in the hood, or make better use of the light you have already got by fitting clip-on light-enhancing reflectors to the tube.
However much light you have, it won’t do any good if it doesn’t penetrate down into the aquarium. Keep the cover glass clean! Murky water will also cut down the beneficial light so make sure a filtration system is not only fitted but also maintained regularly.
You can buy different fluorescent tubes for different purposes: to enhance colors of the fish or to encourage better plant growth for instance.
Modern ‘luminaires’ – fittings which clip on to each side of the aquarium – do away with the traditional aquarium hood. These can be fitted with normal-sized fluorescent T8 tubes or the latest slimmer (and brighter) T5 tubes.
High-intensity metal halide lamps (housed in a pendant fitting) over an open-topped tank are best for large, deep tanks. You will still need a cover glass to prevent damage to the lamps from water splashes.
Keep the lights on for around 10-12 hours each day, as this is what the fish get in nature.
Too much light will result in rampant algae growth. Cut down the amount of light (either intensity and/or duration), plant more plants or introduce some algae-eating fish!
Lamps do not last forever, a fact easy to ignore. Renewing fluorescent tubes every year will ensure that your aquarium never loses its visual appeal.