To correctly size a softener water conditions, water use, and SFR are among the factors to be considered.

All softeners have a variable K based on the salt dose. In short, one can program for maximum salt efficiency or maximum hardness removal capacity or anywhere in between.

Your 2 cubic foot softener (what you call 64k) will only achieve that 64k when the resin is new. Even regenerating at max salt dose will not get you back the entire 64k.

Control valves don't take anything into account. The variables are programmed in and the control valve operates based on the programming.

Exactly my point - you seemed to have just repeated what I said.

Again why is my valve telling me I have 2800 ga available (on startup) since 2800ga * 22 grains ~56k. The resin will be exhausted before 2800 gal have passed through it.

There is no entry for salt dose on the 5600SXT that I'm aware of. It is fixed for max salt efficiency or thereabouts.

I did not repeat what you said. You are not providing all the information needed to correctly program the softener. I have no idea if a 2 cu ft softener is correctly sized for your water conditions, usage, and SFR or not.

The control valve is just doing the arithmetic as you assume. You have to decide the K you want based on the efficiency you want and then program the (C) capacity, (H) compensated hardness, (RS, SF) safety factor, (BF) salt dose, and (DO) day override accordingly.

Do you understand what each step in the programming does?
Did your dealer provide programming info for your specific needs?
Do you have the service manual for your 5600SXT?

This post was edited by justalurker on Fri, Jun 21, 13 at 10:26