Re: GE R.O. Water Filter

[andrew@xxxxxxxxxxxxxxxxxxxx (Andrew Gabriel)]

In article <539dde09-4d18-4e9d-9598-b078062c5570@xxxxxxxxxxxxxxxx>,
	Keith <keseymour@xxxxxxxxx> writes:
> Pat,
> I worked in water purification for some time, the real way to test for a filter that needs changing is the pressure drop over the unit. That applies to the RO unit as well as the prefilter. If you run the filter too long it will rupture and the pressure drop will decrease drastically and all of the impurities will flow into your water.
> For the un-fun part the manufacturer would be the best person to tell you what that pressure drop is to change the filter before you have a problem. In the home automation group I suspect the solution would be to track the pressure drop and have a light green as long as it's increasing and red when it decreases.
> For the most part you are safe because the contaminants are limited to the input side, any additional bacteria that grew would generally grow on the dirty side of the filter. This will increase the pressure drop but not increase your risk.

Some filters have a biocide in them (such as silver) to prevent bacterial
growth. This protection only has a limited life and may require the filter
to be changed for health reasons long before there's enough debris caught
to impact the flow rate.

Similarly, activated carbon filters will run out of pollutant absorbtion
capacity without actually blocking or impeding flow rate - they will
simply cease filtering out the pollutants, and in some cases could even
start releasing trapped pollutants back into the water flow.

--
Andrew Gabriel
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