One of the biggest disappointments of marine fishkeeping is that you can't keep anywhere near the same number of fish in the same sized tank as you can with tropical freshwater species.

Because marines come from 'the largest aquarium in the world' their water conditions in Nature change very little and this is both a blessing and a curse. The good news is that since they all are used to a common water quality, you only need to prepare one kind of water; the bad news is that you've then got to keep that water in tip-top condition, as the fish have no natural tolerance of changing conditions, unlike their freshwater counterparts.

Think along the lines of starting off with at least a 90cm (3 ft) long tank or at least 150 litres (30 Imperial gallons) and you'll be reasonably safe.

Obviously you will make sure the tank is suitable for marine use - no metal frames - an ordinary all-glass, or acrylic, tank will be fine plus, of course, a firm level base or cabinet to sit it on.

You will also need room around, to hang-on, or a place underneath, the tank for the necessary ancillary equipment - and, naturally, the tank should be near a power socket!