Sounds like a semantics thing. Would you think it incorrect to refer to a backwashing iron filter or backwashing H2S filter? I think not.
If I were to add a KL backwashing iron filter, I would not put that existing filter assembly in front. I would ether have the KL as my front end, or I would maybe precede it with a course filter such as a wye filter or a spin-down filter.
Poor choice of words, I meant to differentiate passive (simple filters that do not alter the water's chemistry) vs. active systems like our chlorine injection/green sand setup (a
Pentair WF4, in which induced chemical reactions allow a filter to alter the water's composition) and ion exchange softeners (we have a
Pentair 35952 ) in which electrochemical reactions alter the chemistry of the water.
The
KL backwashing iron filter does seem to be "active" if the claims made by the
Katalox® (PDF 750.7 kB) people are to be believed.
Pentair makes similar claims for the "
high-grade mesh blend of coconut shell-based activated carbons" in their whole house carbon filters (we use their
PC600 unit)
.
OP, I assembled our treatment system after we received "free" testing and a detailed quote from
Pelican Water Systems in Deland FL. They wanted $6225.24; but i went online and bought it all for a bit over $3500--i actually got the WF4 from Pelican, through Amazon. But all three components were readily available from online vendors, all with free shipping.
Any fool, including me, can "cut & paste" PVC pipe...