Models and prices vary, as well purposes and performance (specified as litres per minute of airflow).

There are air pumps for general fish ponds, and you just choose the right pump for a particular pond volume. Complete kits come with with one or two outlets, a length of silicone airline tubing, and one or two airstones. Spares kits are usually also available.

For more demanding ponds containing Koi, seek pumps from the specialists. These pump out more air than those for general ponds, and are usually sold separately to airlines and airstones.

Most air pumps are fitted with rubber diaphragms, but the Medo range uses more reliable pistons instead. These pumps are quiet, compact, efficient, long-lived (10,000 hours life expectancy), oil-free and easily maintained. They are designed to pump to ponds 2m deep and are available in three sizes, with outputs from 28 to 120 litres per minute.

Not an air pump as such, the Oxymax from Oase is an interesting accessory especially designed to attach to Oase's solids-handling Aquamax range of pond pumps. Consisting of a venturi air intake that floats on the surface, connected by a 1m airline to the pump, it provides highly aerated pond water via the pump.