The Tank


Success or not in fishkeeping depends on your ability to provide the fishes with a correct and stable environment in which to live.

Basically, fish require space, light, food, correct water conditions and compatible tank-mates.

In order to start off correctly, you should choose the right tank for the type of fish you intend keeping. There are three main areas of interest in fishkeeping - tropical, coldwater and marine - but unfortunately you can't switch between them as your interests change because they each demand different conditions.

A tank of any given size can, obviously, only support a finite number of fishes but it is not often appreciated, especially by newcomers to the hobby, that this number is not the same for all types of fish.
You can keep many more tropicals in a tank that would otherwise only support a few coldwater fish, and even less marines.

To put it into more practical terms, a collection of tropicals would be happy with a tank 600mm long, coldwater fish would prefer a 900mm long tank whilst marines could need a tank 1200mm long.

Small acrylic tanks with built-on mini-fluorescent lighting are undeniably attractive (especially to children!) but maintaining optimum water conditions in these tanks is much more difficult.

Tank design

Modern tanks are of all-glass or extruded acrylic construction. Look out for optical distortion in the curved shapes and rounded corners of acrylic tanks.

Bear in mind too that each type of aquarium requires different maintenance care, special dedicated cleaning pads are available to suit each type.

Deep tanks are very visually attractive but come with a couple of drawbacks. If the depth is longer than your arms then you'll have problems planting and maintaining it. Also, extra powerful lamps will be needed to get the light right down to the substrate level.

Obviously, given the ability to construct tanks easily using silicone sealant and glass, a tank of virtually any design and shape could be made especially, say, to fit into that vacant corner. Triangular tanks are popular but may be awkward to clean - and just try netting a fish hiding in those acute corners!

Should you decide to make your own tank, bear in mind that attention must be given to the thickness of glass used. As the size of the tank increases, so will the outward pressure from the water and so the thickness of the glass must be increased proportionately. In long tanks (over 900mm) the tendency for the front and rear panels to bow outwards can be restrained by fixing 'front to back' straps across the top of the tank. The aquatic trade operates a quality code to ensure that the correct thickness of glass is used in manufactured tanks.

The overall dimensions of the tank are not exactly critical as long as it is appreciated that a large water surface area as possible is desirable.
It is at the water surface that the important gaseous exchanges occur -
intake of oxygen and expellation of carbon dioxide.

With some 'hang-it-on-the wall' tank designs, the surface area may not be large enough to allow stocking the number of fish that the overall length of the tank implies is possible.

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© FBAS 2004 RCM/RDE          Aquarium Management Care Sheet No 13 1/2

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Last updated July, 2005