On or about Thu, 10 May 2007 13:08:15 GMT did "David Martel"
dribble thusly:

Mike,

I'm not sure why you are going through all of these calculations. If you
set the regeneration time too long you will quickly realize that there is a
problem and do a "manual regeneration" thus throwing all of your
calculations out the window. Your water supply apparently has a variable
hardness so set the regeneration time assuming the highest hardness and your
water will always be soft. If you try to be super efficient about
regenerating you will certainly fail because the actual water hardness
varies. Set it and forget it.

As I specified in the beginning, I have an Autotrol 762/255 head.
That's a metering control head, so I don't set the regeneration time.

I was calculating salt usage. Resin has a variable capacity based on
how much brine you flush through it, and it's not linear. Using 9
pounds nets you 30K grains of softening capacity. Using 13.5 pounds
doesn't net you 13.5/9*30 = 45K, but only 37.5K grains.

So using less salt and regenerating more often uses, over time, less
total salt and more water (more regeneration).

I was looking for someone to verify that my numbers were correct, but
it seems I aimed a bit over most people's heads.
--
- Mike

Ignore the Python in me to send e-mail.