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AQUARIUM UV STERILIZER - ULTRAVIOLET STERILIZER
What is an Aquarium UV Sterilizer?
The aquarium UV Sterilizer is a water filtration device that uses an ultraviolet light bulb to kill
microscopic organisms that are free floating in the water. Parasites, viruses, algae and bacteria
(good and bad) are the type of things that are "killed" after passing through the ultraviolet
sterilizing unit. UV sterilizer devices can be used on swimming pools, in liquid factories (think
beer) and in the home aquarium using an aquarium UV sterilizer. Some large water purification
centers employ some sort of UV sterilization on the outgoing water. These sterilizer units are
also sometimes used in outdoor ponds to help control algae growth and they seem to do a
When using a UV Sterilizer in a home aquarium, the UV unit should be placed last in the
filtration line. You want to first filter the aquarium water through your mechanical filter and
then run the water through the UV device before returning the water to your fish tank. By first
removing the solids in the aquarium water with your mechanical filter (canister filter, etc.), you
are helping your UV unit to attain maximum operational efficiency.
The effectiveness of any UV sterilizer is determined by the UV bulb wattage, the age of the UV
bulb, how clean the quartz sleeve is and the flow rate of the unit.
Aquarium UV Sterilizer Light Bulb
The effectiveness of the bulb will diminish with time and use. Manufacturers usually
recommend replacing the bulb after 6 months. You can find units with bulbs anywhere from 8
watts up to as high as 130 watts. The higher the wattage of the light, generally the more
effective it is. If you have a unit with a lower wattage then you will want to have a lower flow
rate to get the most out of the unit.
Aquarium UV Sterilizer Flow Rate
The flow rate of the unit is an important consideration. Flow rate is measured in gallons per
hour (gph) or liters per hour (lph). While higher flow rates may be acceptable for killing algae
and some bacteria, you will usually need a much slower flow rate to kill parasites. For example,
a 15 watt bulb will usually kill algae and bacteria with a 120 gph flow, but you will need to lower
the flow rate to around 75 gph for it to effectively kill parasites. Read the manufacturers
recommendations for your particular unit for effective bulb wattage and flow rates.
Keep the Quartz Sleeve Clean
One thing that some hobbyists forget about is the quartz sleeve that the UV bulb slips into. You
must clean this quartz sleeve periodically to remove any buildup in order to keep your sterilizer
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