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rgilfert · 05-29-2016, 08:13 AM

Five years ago I installed a Pura UV20-3 whole house water filtration system for our lake water feed. The system is comprised of three components in series: first there is a 5 micron wound sediment filter, second is a 10 micron carbon filter and third is a UV light. Currently my lake pipe is installed in shallow water (< 4') so wave action caused quite a bit of "stuff" to get sucked into the system which causes me to have to replace filters at least monthly because water pressure at the faucet becomes significantly diminished. Comparatively speaking the sediment filters are approximately a third the cost of the carbon filter which I thought would be a good thing because the sediment filter would stop everything 5 microns or larger in size and the carbon filter would let anything smaller than 10 microns through ....... So (in my mind) the carbon filter should never get clogged up. In reality how ever it is the carbon filter that is the bottleneck and needs to be replaced first (or at the same time as the sediment filter). How can this be, it just doesn't make sense to me!!! How is it possible for a 10 micron filter to get clogged when only particles smaller than 5 microns are getting passed to it? What is it that I'm not understanding?

05-29-2016, 08:13 AM	#1
rgilfert Senior Member Join Date: Mar 2012 Location: Bedford, NH / Rattlesnake Island Posts: 299 Thanks: 152 Thanked 227 Times in 57 Posts	Can someone explain this to me? Five years ago I installed a Pura UV20-3 whole house water filtration system for our lake water feed. The system is comprised of three components in series: first there is a 5 micron wound sediment filter, second is a 10 micron carbon filter and third is a UV light. Currently my lake pipe is installed in shallow water (< 4') so wave action caused quite a bit of "stuff" to get sucked into the system which causes me to have to replace filters at least monthly because water pressure at the faucet becomes significantly diminished. Comparatively speaking the sediment filters are approximately a third the cost of the carbon filter which I thought would be a good thing because the sediment filter would stop everything 5 microns or larger in size and the carbon filter would let anything smaller than 10 microns through ....... So (in my mind) the carbon filter should never get clogged up. In reality how ever it is the carbon filter that is the bottleneck and needs to be replaced first (or at the same time as the sediment filter). How can this be, it just doesn't make sense to me!!! How is it possible for a 10 micron filter to get clogged when only particles smaller than 5 microns are getting passed to it? What is it that I'm not understanding?