A pre filter is a particle filter which is installed before a uv steriliser to remove any particles in the water prior to uv sterilisation.
It is important to install a pre filter as if there are any particles present in the water (which may not be visible to the naked eye) then they can stop the uv from penetrating the water properly and therefore allowing bacteria to pass through the steriliser in the shadow of the particles.
For more information please see our Pre-Filter Advice Sheet.
Ultraviolet (UV) sterilisation is a way of killing micro-organisms within water supplies. The micro-organisms can range from bacteria and viruses to algae.
Natural germicidal UV sterilisation from the sun is screened out by the earth’s atmosphere so we therefore need to create artificial UV. This is achieved by converting electrical energy in a low pressure mercury vapour quartz lamp. Electrons flow through the mercury vapour between the electrodes of the lamp which creates UV light.
UV kills micro-organisms by rearranging the micro-organisms DNA, which prevents it from reproducing and therefore rendering it dead. The DNA is altered when UV light penetrates through the cell wall of the micro-organism.
Anything that can cause staining of the UV equipment or affects the colour of the water can affect how well the UV sterilisation works.
Iron and manganese in the water can leave staining on the equipment which decreases the effectivness of the UV sterilisation as the stained colour prevents proper penetration of the UV light. Colour or particles in the water can also dcrease the effectiveness of the UV sterilisation due to ‘shadowing’ , please see our Pre Filter Advice Sheet for more information on shadowing.
Lamps should be changed when the lamp output screen indications but they should be changed about every 12 months.
Filter changes are done according to the water quality, but usually it is three to six months.
Quartz sleeves should be inspected at least every 6 months. If minor deposits have formed, the sleeves should be wiped down with a soapy solution.
For proper operation and disinfection, it is imperative to follow the manufacturer's guidelines on water quality and operational procedures on associated process equipment as well as on the UV equipment
Filter cartridges need to be replaced every three months however changes in taste, colour and water flow indicated that the filter needs to be changed.
You can change the filter cartridges by following our step by step instructions on our How To Change Filter Cartridges Advice Sheet.
It is recommended, depending on the water condition, to replenish the filter media every twelve months.
You can change the filter media by following our step by step instructions on our How To Change Filter Media Advice Sheet.
Martin Simpson Managing Director Deeside Mineral Water
Witek Mojsiewicz, Aquarium Manager, Macduff Marine Aquarium
Mr Hamilton Smith Forgie
Debbie, Manager, Happy Plant Garden Centre, Mintlaw