Used in marine aquariums, this is another method of removing organic material from the water.
This is achieved by using fiercely aerated water within the filtration unit: organic matter is attracted to the water/air bubble interfaces and the resultant pollutant-laden foam is collected in a chamber from where it can be regularly emptied.
Ultra Violet Units, used correctly are sterilisers and are capable of 99.9% sterilisation of water. Used in conjunction with a filtration system, they will indirectly clear algal growth (Green Water) in pond or aquarium and have a place in practical fishkeeping if used correctly.
UV Light can be dangerous and such units should be used with care and discretion.
Similar, but not so generally known, are Ozone generators. These utilise high voltage discharges to generate ozone which, unless properly controlled and dissipated, can be just as effective in killing off your fish as well as all the potential nasties at which you aim it!
Marine aquariums can also use very sophisticated units in order to keep water conditions perfect.
Kalkwasser units can automatically add calcium as and when required.
External Trickle Filters and de-nitrifying units are also used. Much of this extra equipment can be housed in the cabinet below the main aquarium.
© FBAS 1998 RCM/RDE Aquarium Management Care Sheet 1 2/2