Aquarium Tank
The type of tank you buy depends to some extent on the sort of fish-keeping you intend to pursue. Generally speaking, it is a false economy to buy a small tank, for a number of important reasons. Firstly, a small tank will almost inevitably be atop small tank — i.e., it is likely to be overstocked — and this is dangerous to the fish. More important, the larger the tank, the more stable it is as an environment, and the more the whole system is able to resist changes which could damage the fish. Beginners, who often start out with a small tank, are also the leas table to anticipate problems and head them off at an early stage. So always buy the largest tank you can afford and can safely accommodate. Although many fish will live in small tanks, it is best to start with one of at least 901 (20gal) capacities. This will be approximately 60cm long, 30cm in breadth, and 37.5cm in depth (24×12x15in), and will weigh about 90kg (2001b). Marine fish require even larger tanks than freshwater fish.
For many years, steel-frame aquaria were the rule, but these have now been generally superseded by all-glass tanks. These remade from five sections of plate glass, bonded along their edges with very tough silicone rubber, and are extremely strong. They have the added advantage that they avoid the unsightly frame of the older type of tank. But remember that, the larger the tank, the thicker the glass has to be: for a giant tank of lm (40in) depth, the side would need to be of at least 13mm (1/2in) plate glass, and the Bottom nearly 2cmtanks is not really practicable. However, due to the simplicity of the construction, aquarium manufacturers can rapid!’ makes up a tank of any special size to fit a particular corner or alcove you may have.
Bonded-glass tanks of this type have many advantages over the traditional variety. The seal is slightly flexible, and will not leak if the tank shifts slightly. The tanks are comparatively light and are cheaper to make; and, having no internal gaps around the edges, they are easy to clean and will not allow contaminants to seep into the water.
Small tanks do have their place — for breeding purposes, or as quarantine or hospital tanks. Small metal- or plastic-framed tanks can be used for these purposes, but must never be used for marine fish. Not only is saltwater much more proficient at corroding metal than is fresh, but these fish are very sensitive to dissolved metals or other substances in the water. So use only all-glass or all-plastic tanks.
You may be offered an old metal-framed aquarium for renovation for freshwater use. If you want to use it, first strip it down. Remove or knock out the old glass (it is almost impossible tore move it without breaking it). Chip out the dried putty or mastic, and sandpaper all the rust off the frame. Paint the whole frame with rust-proofing primer as used for cars, followed by a layer onion-toxic gloss paint, which must be allowed to dry thoroughly
The glass must then be sealed in using special aquarium putty or, preferably, aquarium mastic. Neither substance dries out com-politely, so you obtain a slightly flexible seal. Start off by running strip of mastic around the bottom edge of the frame, and then seat the bottom glass (this can be wired glass, for extra strength). Add the sides, pressing the glass carefully against the mastic to bed it indwell. Stand the tank on a flat surface and fill it cautiously; excess mastic will be pressed out and can be trimmed off tidily. Leave the tank filled with water for at least a week, and then empty and clean it thoroughly before setting it up with fish and plants.
All aquarium need some form of cover. Without one, many fish will be able to jump out and be killed. In addition, the rates of evaporation and heat-loss from the water surface will both be very high.
Special plastic clips are available to suspend a sheet of glass just below the top edge of the tank so that condensation can drip back into the tank and the need for frequent topping-up be reduced. Small gap is left around the edges for air lines and electrical cables.
Artificial lighting is required, and must be in the form of mini-nature fluorescent tubes; these produce very little excess heat, unlike ordinary light bulbs. However, the color of light they produce can be rather unnatural. It is best to buy special tubes manufactured for horticultural use: these produce a purplish-colouredlight which both enhances the colors of fish and stimulates plant growth. You can buy a plastic or metal hood to contain the lights; this simply stands on the glass cover. As with all aquarium electrics, it is absolutely essential that this is properly earthed, and connected by a fused plug.