The pre-filters included with the SPS series satisfy the minimum pre-filtration requirements for the UV sterilizer and may help to improve UVT by removing sediments and organics. All UV sterilizers require sediment pre-filtration to reduce or eliminate the possibility that a targeted contaminant could "hide" behind a sediment particle in the "shadow" of the UV light and therefore not receive a full dose of UV light. Accordingly, the manufacturer strongly recommends sediment pre-filtration down to a level of 5 microns or smaller.
Water exceeding 120 ppm in hardness (7 grains per gallon) should be softened or treated with a salt-free hard water conditioner to reduce the risk that hard water mineral scale will build-up on the UV sleeve thereby reducing UV light distribution into the UV chamber. Similarly, iron levels exceeding 0.3 ppm or manganese levels exceeding 0.05 ppm should also be treated to prevent staining of the UV sleeve.
Elevated levels of certain other contaminants, such as tannins, can cause a reduction in UV transmittance (the ability of the water to transmit UV light). If the UV transmittance (UVT) of your water is less than 75% after the above-mentioned pre-treatment, activated carbon filtration may be desirable to improve UV transmittance. The majority of deep wells have a UVT of 85% or greater. If your UVT is unknown, select a model with a higher flow rate capacity than the one you originally sized at 95% UVT (this will provide a higher UV dose at your desired flow rate), or add an activated carbon pre-filter to your system.
We recommend that you have your water tested for the following parameters before selecting a UV sterilizer. Proper pre-treatment to ensure that your water meets these parameters will maximize the performance of your UV system. It will also reduce your maintenance requirements. If your conditions do not meet these parameters, please contact us free to discuss pre-treatment options or to discuss how the performance of your UV system will be affected.
