Monday, December 2, 2013

Disinfecting Spring Water with UV Sterilizers


I live on a rural property and my water supply is from a spring. I know that the previous owners would use bromine every couple of years to insure bacteria free water, although they never actually had a "bad" water test. The capacity of this spring is 15 gpm and is for the household water supply (not irrigation). What capacity of UV filter would be appropriate for this type of system? I do not want to deal with back filters etc if I don't have to. I am also on a fixed income, so money IS an issue.


Karen B.


Illustration of Giardia cysts
We recommend a Wonderlight GN-15 for your application.  These low-cost sterilizers are rated for 15 gallons per minute, are NSF-certified, and will completely destroy bacteria like Giardia and E. coli.  Plus, Wonderlight sterilizers are easy to install and use, long-lasting (their UV lamps are rated for 9000 hours of use), and efficient (pressure drop of less than 5 PSI at flow rate of 12 GPM).

Note that water should be low in hardness and free of iron, manganese, and sediment before being disinfected with UV light.  If you already have pre-filters, all you'll need is to install the UV sterilizer at the end of your system, just before the water enters your house.  

Doulton Rio
Filter Housing
If not, we recommend installing Big Blue dual grade filters before your UV system.  A 50/5 micron cartridge filter followed by a 25/1 micron cartridge filter should do the trick, though if your spring water is exposed to air we recommend using a Doulton Rio ceramic filter instead of the 25/1 filter, as this ceramic filter is very good at removing giardia and other parasites such as cryptosporidium.  Plus, Doulton filters use silver-impregnated ceramic to inhibit the growth of bacteria and imbue the filter with self-sterilizing properties; this means you won't have to boil it to remove impurities from the ceramic pores, as you might with other filters.

We hope this helps you find the right UV sterilizer for your spring water, Karen.  If you'd like, see our Practical Guide to Ultraviolet Sterilizers for more information.  If you have any further questions about ultraviolet treatment (or otherwise) you can reach us at, on Facebook, or through our online contact form.  Thanks for the letter, and good luck!