About invertebrates and corals

The beauty of a marine aquarium

There are two main types of marine aquarium, one being an environment just to keep fish, with no invertebrates. This is generally known as a “fish-only” aquarium. The other is a “reef tank”, which houses both compatible fish and invertebrates, to form a miniature representation of a coral reef.

Marine fish have been kept in captivity for many years now, but it is the home marine aquarium that has really become so hugely popular worldwide today. No longer the preserve of the larger public aquariums and institutions, the spectacular beauty of a marine aquarium can be within the domain of most interested would-be fishkeepers.

Caring for your reef tank 

Like the “fish-only” marine aquarium the reef tank requires excellent filtration. The lighting is a more important consideration, as it will play a big part in the success or otherwise of the sessile invertebrate pieces.

Most hard corals and anemones need to have strong lighting to support their life processes and LEDs are one recommended type to have over the reef aquarium for maximum effect.

A bank of high intensity output fluorescent tubes provides an alternative lighting set-up. However, not all the inverts will appreciate being exposed to the full glare of such lighting, as in nature they favour overhangs, rocky niches, and the more shaded areas of the reef away from direct sunlight, and should be placed with thought in the reef aquarium.

As with any marine aquarium the water quality is of paramount importance, and regular part-water changes are vital to the success of the reef tank. Maintaining the essential perfect water chemistry while addressing the feeding needs of the population within the aquarium demands a careful balancing technique which careful trial and error will perfect.

Most corals, sponges, tunicates, and other sessile invertebrate animals feed by filtering the water and removing suspended nutrients from it. When applying liquidised foods for this purpose, it will be necessary to reduce or turn off the wavemakers for a short time to give the inverts a chance to gather in the particles before the current does. Shrimps and tiny crabs will scavenge the nooks and crannies inaccessible to the fish, but their intake will be quite restricted, and it is not practical to rely on these tiny creatures to clear up gross overfeeding.