Re: Water pressure measurement

["RF Dude" <post@xxxxxxxxxxxxxxxxx>]

I have the same interest.  I've been experimenting with my 5-stage RO
system.  I put a pressure gauge after the pre-filters and just before the
membrane, but it never really shows any drop in pressure.  Not enough flow
to show the effect of a really dirty filter.  The carbon filters are
actually used up long before it would show as a pressure drop.

Another way to do this would have been a FLOWMETER.  This way one can
measure the amount of water that has passed.  Filter replacement would be
triggered based on the capacity the filter manufacturer states.

For whole house filters and high flow rates, the pressure gauge would seem
like a good idea.  A differential type pressure switch could automate this?

In the end for the RO system, I got a chlorine detection kit that turns the
water pink if chlorine is present. At six months, I tested the water after
the first, then second carbon stage and found that chlorine was beginning to
appear on the output of the first carbon filter.  So I now change the first
carbon every 6 months, and both carbons and the sediment filter every year.

On ebay, you can also get in-line TDS meters relatively cheap.  But if one
waits to see the effects of a failed membrane, it is too late!

Good Luck!