Decorating Marine Aquarium
Coral is the most natural material for decorating the tank, and canbe bought from marine specialists. It is the limy skeletons of tiny anemone-like creatures, and although it will have been cleaned it will still contain organic matter which can foul the water veryquickly. Soak all coral in a strong solution of bleach — one cupfulper 5 litres (1.1gal) — and leave it for at least a week, repeatingthe process with fresh bleach for another week. Then soak it for several days in fresh water until all trace of the chlorine smell is removed. Only now is it clean enough for use.
Coral is usually white, and comes in many forms. There is adark red type called organ-pipe coral, which is very useful as it canbe easily cut or chipped into caves in which fish can hide, orshaped to conceal heaters. Another type grows in heavy sheets andslabs, and is pale blue. Coral of any other colour is dyed, and must not be used. Do not use sea-fans or sea-whips, which are rubberycorals which gradually break down in the tank. Stone can be used in the marine aquarium, limestone or York stone being the mostuseful.
You can construct a coral reef in the tank by cementing individual blocks of coral together with silicone adhesive. However, itis best to leave corals or rocks loose so that they can be shifted to allow proper cleaning of the tank. You may have other good reasons for moving the coral, such as to break up
by aggressive fish when you introduce new tank mates.
You can buy so-called ‘living rock’ — stones complete encrustation of living plants and animals. Unfortunately,only be used in a mature aquarium, where water condition become established. It will then be welcomed by the fish, who very quickly chew off all traces of any edible organisms.