Low Pressure UV Sterilizer

Low Pressure UV Sterilizer

Low Pressure UV Sterilizer

UV sterilization systems are gaining popularity as an effective method to disinfect air, surfaces and water. They can also reduce volatile organic compounds and eliminate unwanted odors in the air.

MAT-KULING offers high efficiency low pressure UV lamps that convert up to 40%* of electrical power into UV-C radiation 254 nm. They offer a lower operating cost than medium pressure systems while providing the same reliable germ kill and chlorine reduction.


Unlike medium pressure UV lamps, Low Pressure UV Sterilizers produce monochromatic radiation (254 nm) with a higher output. This means they can be used to sterilise water, surfaces and air, and also help to control unwanted odours.

Ultraviolet rays can be used to disinfect surfaces, liquids and gases by breaking down the DNA structure of bacteria. This kills them immediately and prevents them from reproducing. Low Pressure UV lamps have a wide range of Low Pressure UV Sterilizer applications in both domestic and industrial environments, such as the disinfection of drinking water and swimming pools, and the treatment of process water for food production.

Many aquarium and pond retailers sell models of UV Sterilizers that are marketed as ‘Kill Machines’. In reality these do NOT kill all dinoflagellates in a marine aquarium, even at very low flows, they are level one capable only (which is why they show up at the top of Google Searches) and are more accurate in their description as “UV Clarifiers”.

A level one capable UV Sterilizer will however, clear a large amount of cyanobacteria, green algae and other nuisance dinoflagellates, and at lower flow rates can aid in parasite control by improving fish immunity. This is a significant benefit over using a quarantine tank, and will assist in keeping a well balanced Redox potential in Reef aquaria. For the best results it is recommended that the UV be plumbed in after your filter, and not before it as this can create a film or mineral build up on the lamp and sleeve, blocking some of the light. The use of a PVC T or Poly Insert Hose Barb ‘T’ diverter is preferred over the built in diverters often found on popular UV Sterilizers, as this reduces turbulence at the point of water entry to the UV, and allows for better water flow through.

Flow Rate

The more contact time that a microorganism has with UVC, the more thoroughly it is killed. This is why higher turn over rates (in aquarium/pond systems) and longer dwell times are preferred to shorter bulbs as the lower wattage lamps have a tendency to “burn” the water by irradiating it too quickly thereby lessening its killing power.

To achieve level one sterilization in an aquarium, a 7.5 watt lamp should be used with a turnover rate of about once every two hours (assuming that the aquarium/pond has sufficient pre filtration). Ideally, the UV Sterilizer would be plumbed to a pump that provides at least 400 gph for circulation and this is why so many popular Aquarium and Pond UVs fail (many with built in flow through diverters that must be ‘twists’ or ‘wiped’ as shown in the photo below) as they have poor design in terms of flow for the specific wattage of the UVC bulb/lamp.

This is also why a Custom UV Sterilizer is often a better option than a’standard’ internal aquarium/pond UV that is mated to an inline water pump, valve & or diverter. The Custom UVs I build have hose barbs that are smaller than the pump inlet ports and this helps keep the overall flow rate down so that the level one UV can properly sterilize the water. This is important as higher levels of UV can aid in parasite control but not by actually killing the ciliate Epistylis which is distantly related to Ich/Crytocaryon, rather by improving the fish’s immune system and helping it fight off this common fish disease.

Lamp Life

Unlike red light, UVC rays have one useful peak output at 254 nanometers. These rays Low Pressure UV Sterilizer penetrate all the way through the bulb to kill microorganisms in your water. They also interact with water molecules to dehydrate them and make them more brittle. This process is known as photo-oxidation and it kills bacteria, algae and other microscopic organisms that can be found in your water.

Some UV sterilizers are designed with shatterproof lamps that have a polycarbonate sleeve around them. This prevents glass shards and mercury from being released in the event of a break. However, the sleeve can also block a small percentage of UVC output from reaching your water. This is why it’s important to choose a sleeve made from the highest quality material to ensure that your sterilizer will continue to disinfect water even after the lamp has reached its end of life.

It’s also essential to understand how often you should replace your UV bulb. A good rule of thumb is to change the UV bulb every 6 months for disease prevention or at least once a year for green algae prevention. You should also clean the quartz sleeve at this time to help extend the life of your UV sterilizer.

Remember that every time you turn your UV system on and off, it uses energy to start up the lamp and warm up the water. Over time this will eat away at the 9,000 hour lifespan of your UV lamp. So, it’s important to keep a spare UV lamp on hand or set a reminder to order your new bulb a month before the old one expires.


UVGI works by exposing micro-organisms to short wavelengths of the light spectrum. It’s harmful to them and damages their nucleic acids, disrupting their ability to reproduce and ultimately killing them. It does not change the water’s chemical composition and has no secondary pollution issues, unlike chloride disinfectants that can leave residues in the water.

The polychromatic output of medium pressure UV lamps allows it to inactivate organisms through protein degradation and enzymatic breakdown as well as DNA destruction, which is why it’s effective against a wide range of organisms. However, some strains of organisms may require 1.5 times the dose of other strains to be effectively inactivated.

To ensure the highest level of UV disinfection, a number of parameters need to be taken into consideration such as power fluctuations that impact the EM wavelength, the presence of protective particles, and the microorganism’s ability to withstand UV. This is why it’s critical to use a qualified 3rd party laboratory to conduct a bioassay on your water treatment system before the first operation.

atg UV Technology’s end-feed closed vessel chamber design can be installed inline directly into the pipe vs constructing open channels, significantly reducing both the capital and operating costs of your project. Typical CAPEX savings are 15% – 20%. Operational cost savings include reduced power consumption, lamp and quartz costs, less maintenance time, increased electronic ballast life (new modern design) and the elimination of the need for costly civil structures.

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