UV Steriliser Buying Guide

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UV Steriliser Buying Guide

Maintenance of aquariums, which entails cleanliness and water replacement, filter changes or choosing water pumps, is an imperative factor in keeping fish and other aquatic organisms. There is a lot to take into consideration in the environment of a fish aquarium such as algae, parasites, bacterial diseases, and other micro-organisms. Fortunately all the necessary equipment is available to buy simply and easily on eBay. In order to prevent your aquarium from being plagued by such conditions, a UV steriliser can help you get rid of and combat the problem, and there is a wide range available to fit all aquarium types on eBay.

UV Sterilisers: How They Work

Ultraviolet sterilisation is a proven, dependable, and effective method for controlling and eradicating algae spores, bacteria, and protozoa present in a water environment such as a fish aquarium.

* UV sterilisers destroy disease-causing pathogens as water is pumped through the unit.

* They accomplish this through use of a special fluorescent lamp that emits light at a wavelength of 253.7 nanometres.

* Aquarium water pumped through the UV chamber is exposed to this UV light and is irradiated.

* Free-floating microorganisms in the passing water are affected by the UV light and are no longer able to multiply.

* Through continual use, UV sterilizers can help manage water quality issues due to microorganisms such as bacteria, algae, and parasites.

UV light targets the smallest of microorganisms, without harm to the other aquarium inhabitants. It works by altering the invader's genetic material. This ultimately shortens the organism's life cycle, thereby limiting its reproduction. Thus, a single cell exposed to UV irradiation has less chance to blossom into an algae bloom or rapid-spreading disease.

Choosing The Right V Sterilizer For The Aquarium

The following questions are useful when buying a UV steriliser on eBay:

* What kind of organisms need to be controlled? Bacteria, algae, or micro-parasites?

* Which style of UV steriliser (in-line/hang-on) will best suit my existing aquarium system?
UV Sterilisers are recommended for all saltwater and freshwater aquariums, as well as for ponds.

Organisms eliminated by UV sterilizers

* UV sterilisers will eliminate protozoan parasites such as ich during the new born, free-swimming life cycle stage of the parasites.

* UV sterilisers will sterilise free-floating algae.

* They do not eliminate the ich parasites once attached to the fish. If this is the case, UV sterilisers must be used with other methods to treat ich.

* It will not sterilise algae that has adhered to glass or become embedded in live rock. The algae need to go through the UV steriliser to be sterilised.

Different UV Steriliser Styles

The specifications of UV sterilisers differ in a number of ways. They are differentiated by two features: Their mounting style; and the manner in which water flows through them. They are categorised into the following:

In-line Sterilisers

In-line set ups are plumbed directly into the main aquarium filtration system. The UV is placed after the mechanical filtration unit and should be the last in-line device before water returns to the aquarium. Generally a ball valve and bypass are used to adjust the flow rate through the UV steriliser. Most in-line UV sterilisers are designed for larger aquariums and incorporate higher wattage bulbs encased in a long, cylindrical housing. Hobbyists often prefer the in-line set-up because it removes the somewhat unsightly piece of equipment from view as compared to the hang-on set-ups.

Hang-on Sterilisers

These are compact sterilisers and are mounted directly to the back of the aquarium. They are generally used as an independent device fed by a submerged power head. However, some hang-on sterilisers may also be connected to the return line from a canister filter or in-line filtration systems. Hang-on models tend to be easier to install and maintain, making them ideal for smaller aquarium setups. Generally, due to their relatively smaller size, a lower wattage bulb is used for hang-on sterilisers. However, to maintain efficient UV sterilisation, these smaller units have a unique internal design. To maximize UV sterilisation, a spiral or stepladder design is incorporated to extend the length of time the water is exposed to UV light.

Depending on the size and the particular aquarium setup, one mounting style may be more convenient to install than the other. Regardless of the difference, UV sterilisers require a water pump or circulation pump and plumbing (sold separately) to transport water from the aquarium, through the UV chamber, and back into the aquarium. UV sterilisers have many advantages and very few drawbacks. In addition to being easy to install, requiring low maintenance, and being affordable, they can provide huge health benefits for the fish. Make sure to get one that is the correct size, operate it under the appropriate conditions, and follow the manufacturer's maintenance guidelines to ensure optimal performance.

For optimal performance of a UV Steriliser, ensure it has the following

* It must possess a low-pressure lamp to produce virtually all of their UV output at a wavelength of 254 nanometres, and it ensures a useful life of 8,000 to 12,000 hours, depending on the operating current of the lamp.

* It must have a 3 to 5 inch diameter body, because the design specifications determine the unit's UV "dose rate" at any given water flow rate.

* It must position the UV lamp between the water inlet and outlet ports.

* It must enable water flow rate to be based on lamp life performance.

* Remote power supply must be suited well away from the UV steriliser body.

Installing and Maintaining the UV Sterilizer

When using a UV steriliser in a home aquarium, the UV unit should be placed last in the filtration line. First, the aquarium water should be filtered through the mechanical filter and then run through the UV device before returning the water to the tank. By first removing the solids in the aquarium water through the mechanical filter (canister filter, etc); the UV unit can attain maximum operational efficiency.

The effectiveness of any UV steriliser 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. It is possible to 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 the unit has a lower wattage, a lower flow rate will be required to get the most out of the unit.

Aquarium UV Steriliser Flow Rate

The flow rate of the unit is an important consideration. Flow rate is measured in gallons per hour (gph) or litres per hour (lph). While higher flow rates may be acceptable for killing algae and some bacteria, a much slower flow rate is needed 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.

Quartz Sleeve

The quartz sleeve must be cleaned periodically to remove any build-up in order to keep the steriliser operating at peak efficiency. The better steriliser units have a wiper with a handle outside the unit that allows quick and easy access to clean the sleeve without taking out the steriliser apart.

UV steriliser bulbs with four pins at one end should be replaced once a year. Lamps with two pins at each end should be replaced every six months. They will lose intensity over time and after these respective periods of time the loss in intensity is likely to be critical.

Buying a UV Steriliser on eBay

eBay has many sellers selling UV sterilisers in both used and new units.
Aquarists are divided on the decision for buying a UV steriliser or not. For those that may be deciding on whether a UV light filter should be added, here are some other points to consider.

* A UV steriliser is most effective when run all the time and if the water is clear.

* They are most effective if bulb is new, or replaced regularly (at least every 6-8 months).

* Effectiveness can be hindered if the water passes to fast past the bulb, as the optimal exposure time of the water to the UV light is longer than one second.

* It can help to prevent water borne pathogen culture from reoccurring, once the initial problem has been completely eradicated from the aquarium.

* The effectiveness of UV light can be hindered if there is light blockage, i.e. a salt encrusted bulb.

* UV light not only kills unwanted organisms, but can also harm beneficial ones as well, as it

* It only destroys organisms that are free floating in the water as it passed by the UV light. It will not, for example, get rid of an ich infestation that is already on fish, or cure a bacterial disease fish may have.

* It should never be run when treating with any drugs or medications.

* UV can also alter the structure of some dissolved chemical compounds.

* UV light can be damaging to the human eye, so never look into the bulb.

* Always unplug the unit when working on it to prevent possible shock if it breaks or gets wet.

To view the range of UV Sterilisers on eBay, go to the category menu and select Pet Supplies and then choose Cleaning/Water Treatments. UV sterilisers can be found among the collection here, and the search function can be used to further narrow down results, such as by typing 'UV steriliser' into the search bar.


Whichever steriliser is chosen, it must be the right type, and be properly fitted for the specific aquarium to ensure a healthy and happy quality of life for its inhabitants. Now that you are aware of all the factors to take into consideration, you are equipped to make an informed selection from the options available on eBay.

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