"Dave" wrote in message ps.com...
I am about to get a water purification system for my house which uses
a KDF-55 pre-filter. Anyone out here have any experience with this?
I've searched old forums, but no joy. I don't want to ask the company
rep about it; they'd just probably shoot me a line anyway...

Did you ask what is inside KDF-55 "prefilter"?
And how is the main filter working?
Such systems are usualy water softener systems...
Just to remove large rust particles and calcium hardness.

For reef tanks we usualy use multi-stage filters with main
stage being reverse-osmosis (RO) and the last stage using
ion-exchange resins (called de-ionisator, DI) further polishing
water coming out from the RO filter. As a result we receive
pure water, cleaner than distilled water you can get in the
grocery stores.

Rather than whole-house purification system we use
such RO/DI filters just for drinking water and to fill up
tanks for mixing sal****er.