General FAQ

These questions are general water-related questions, not necessarily product-specific.

  • Do I need to disinfect my municipal water supply?

    Municipalities work very hard to provide safe water for their customers however, aging infrastructure can introduce contamination into the water lines even after the water has been treated at the treatment plant. Complete confidence in water safety falls to the homeowner.

  • How do I know the system is working?

    Our systems come equipped with both audible and visual alarms which will notify the homeowner if their system is not functioning properly. It is important to regularly clean your lamp sleeve and replace the UV lamp annually to ensure the system is properly functioning. Some UV systems are equipped with UV sensors, these components measure the intensity of the UV lamp ensuring adequate UV dose is achieved.

  • How much does it cost to operate UV systems?

    UV systems are extremely economical to operate. A typical UV system operates on the same power requirements as a 40 watt light bulb!

  • Will UV change the taste of my water?

    No, as UV purification is a physical process, it does not change the taste or odor of the water. It simply provides safe, reliable purification and adds nothing to the water. Please note, though, that if your water contains hydrogen sulphide (noticeable by a smell of rotten eggs), the scent may be slightly improved after UV treatment but UV will not remove the smell significantly.

  • Should I shut my system off when I am not using it?

    No, the UV system should be left on whether you are using the water or not. The lamps age regardless of the amount of water drawn through the system. By leaving the unit on, you will eliminate the potential problem of having contamination pass through the system while the unit is off. However, if water is drained from your purification system (e.g. winterizing), the UV system must be switched off. During other long periods of non-use (e.g. vacation home), the system can be shut off to save power and lamp life provided shut off valves are used on either side of the UV system preventing untreated water or bacteria from passing through the UV chamber while not in use.

  • What are the annual maintenance requirements?

    UV lamps have a useful life of approximately 9000 hours which means that the lamp should be replaced annually. Please be aware that the UV light may illuminate beyond one year, however, there will not be enough UV energy to provide adequate purification. Proper maintenance of any pre-treatment is also required. The sleeve should be cleaned at least once a year, and changed every second year.

  • Do I need to consider the quality of my water prior to the UV?

    Yes, for UV to be effective, it is recommended that the influent water contain the following: Iron < 0.3 ppm (0.3 mg/L) Manganese < 0.05 ppm (0.05 mg/L) Hardness < 7gpg Tannins < 0.1 ppm (0.1 mg/L) Turbidity < 1NTU UV transmittance > 75% Note: These calculations are minimums and it is best practice to re-treat beyond these values. If you are unsure of the quality of the water supply, it is imperative to have the water tested. A UV transmittance test (UVT) is strongly recommended for problem water, or water that is colored (eg. surface water supplies). To find out more information about UVT tests, please contact VIQUA for further information.

  • How do I control the water flow?

    As the UVs are designed to operate at a specific flow rate, it is imperative that the systems operate within this design. The use of flow restrictors are recommended to control the flow of the unit. A true flow restrictor designed with a variable orifice that fluctuates based on water pressure is the only flow restrictor that is recommended as those that are simply a “flat washer with a hole in it” do not regulate the flow based on variances in water pressure. As the variable orifice may not be extremely resistant to UV, it is recommended to install the flow restrictor at least 6″ away from the outlet port (axial flow reactors can install restrictors directly on inlet port).

  • Does UV treat E. coli?

    Yes, E. coli requires a UV dose of between 6 to 10 mJ/cm2 to achieve a 4-log (99.99%) purification. This is well within the capabilities of VIQUA UV systems which actually deliver a minimum of 30 mJ/cm2 at their quoted flow rates.

  • Is UV effective against protozoa such as Cryptosporidium and Giardia lamblia?

    Yes, as a result of recent findings by academic researchers, it has now been proven that UV is the best available technology to treat these protozoan cysts. In addition, the dose levels required to inactivate these cysts are actually quite low: less than 10 mJ/cm2 for 4-log (99.99%) reduction of both Cryptosporidium parvum and Giardia lamblia. This is well within the capabilities of VIQUA UV systems which actually deliver a minimum of 30 mJ/cm2 at their quoted flow rates.

  • Is UV 100% effective?

    The effectiveness of UV is not as simple as a "yes or no". UV will at some level of "Dose" inactivate all microbes. Once the target dose for the target organism is understood, effectiveness is measuring using log reduction, 1 log = 90% 2 log = 99% 3 log 99.9%. Generally speaking a 4 log reduction 99.99% is standard.

  • Do I need any pre-filtration?

    Yes, as microbes can potentially be shielded by suspended particles (turbidity) in the water supply, it is necessary to filter the water to remove these suspended particles. A high quality graded density filter cartridge with nominal micron rating of at least 5 microns is recommended. Keep in mind, UV is a component of a total water treatment system, following the specifications above will produce varying system place to place. A "filter" is not always suitable to produce adequate water.

  • Why do I need to purify my water supply?

    Purification is strongly recommended for all water sources including municipal water, due to ever changing water and old decaying infrastructure. Testing for indicator organisms should occur in both the spring and fall.

  • Will the UV affect my water pressure?

    No, the UV systems are designed with inlet/outlet ports correctly sized for the specific application. As an example, the 10 gpm system comes with 3/4″ ports. The typical pressure drop on this system would be 2-3 psi. Any system with a flow restrictor installed will encounter an increased pressure drop as the system nears the maximum flow rate it is capable of delivering.

  • As UV has no residual, how do I make sure the entire distribution system is free from bacteriological contaminants?

    To ensure a bacteriologically-free distribution system, it is imperative that the entire water system located after the UV is chemically disinfected. This is easily accomplished by filling the pre-filter with 1-2 cups of household bleach and allowing this to flow through the system. While doing this, you must ensure that all taps, including outside faucets, dishwashers, washing machines, etc. pass chlorinated water. Once you detect the bleach at the faucets, shut the faucet off and wait a minimum of four hours to allow adequate disinfection. Return to all locations and flush the chemical disinfectant from the system. Make sure the UV is on during this procedure. Remember to have your water tested on a regular basis to ensure that your system is operating correctly.

  • Why are two different wavelengths used in water treatment?

    Two different UV wavelengths are employed in water treatment 254 and 185 nm. 254 nm UV light is called the germicidal light because of its ability to inactivate microorganisms. It penetrates the outer cell wall of the microorganism, passes through the cell body, reaches the DNA and alters the genetic material, destroying the organism.

  • In the Chlorine/Chloramine removal process, what advantages does UV treatment have over the conventional methods?

    With UV, there are no side effects to overcome because no chemicals are added which have to be removed later.

  • Describe a typical UV water treatment unit and how it works.

    A typical UV unit works by irradiating flowing water using UV lamps strategically placed within the treatment chamber. Although the water resides within the chamber for only a few seconds, it receives sufficient UV dosage to be lethal to microorganisms present in the water. A dosage of 30 mJ/cm2 is more than sufficient to destroy most water-borne microorganisms.

  • What are the primary benefits of ultraviolet water treatment?

    Ultraviolet (UV) light treatment is a widely recognized and proven method of disinfection of water. It is a physical treatment, not chemical, so it doesn’t alter the water chemistry. UV adds nothing to the water such as undesirable color or odor and it does it generate harmful by-products

  • Should I be concerned about the adequacy of my electrical system?

    The UV system does require consistent power, both voltage and frequency, to operate effectively. To compensate for variations in power supplies, VIQUA systems incorporate proprietary electronic ballast technology. The electronic ballast provides a constant output voltage regardless of variations in input frequency or voltage. This results in consistent UV output and consistent UV dose. It is recommended to install the UV on a separate outlet protected by GFI (ground fault interrupter). In applications where power fluctuations and surges are common, a surge protector or UPS is recommended to preserve the system.

  • How much space does a UV system require?

    As the UV lamps and/or sleeves need to be periodically removed from the UV chamber, you must leave a least double the length of the disinfection system to facilitate removal.

  • How do I clean the quartz sleeve?

    If the quartz sleeve becomes stained, remove the sleeve from the reactor chamber and clean with a commercially available scale remover such as Lime-Away or CLR. Always use an acid based product. It is also important to use more than visual perception with this component, place the sleeve against a white sheet of paper to ensure is transparency. If the sleeve seems discolored after being cleaned with recommended products; replace it.

  • What size of system do I need?

    VIQUA offers many different models in sizes ranging from 1 gpm to 80 gpm. An average household UV ranges in size from 5 to 12 gpm. Determining your pump’s flow rate will typically determine your required flow rate. It is important to never under size the UV; when in doubt about the size, always choose the next largest size. A simple way to test your flow rate is to take a 5 gallon pail and fill it directly from the pressure tank. If the pail fills in 60 seconds you are achieving a 5 gpm flow rate, 30 seconds 10 gpm etc.

  • What industries use UV water treatment?

    It is a well-proven technology and multiple industries use UV technology for water treatment. Examples include pharmaceuticals, food & beverage, aquaculture, recreational water, municipal drinking water, etc.

  • Should I install a by-pass assembly?

    Although not essential, the installation of a simple by-pass assembly would allow for emergency use of the water in case the UV system was required to be removed from service. A simple by-pass assembly with three isolation valves can be installed quite easily.