Yes, yes, and yes. I agree that going higher is better than going low, when sizing a system. When I did mine, based on all of the advice here, I used 60 GPPPD. See, I listen!! But... here we are talking about he difference between meters and clocks, because he already has his system in place, and is trying to understand how to set it up more efficiently. He KNOWS he uses less than 60/75. Granted, the average person looking to purchase a softener would not know this, unless they had a meter they were actuallt tracking usage with.
"How do you program a day timer differently than a metered softener and what water and salt savings would the average family have?"
Surely you know the difference, and you are just pulling my chain? But I will humor you... with a clock, one estimates the GPPPD, decides how many days they want per regen as wel.l as how much salt ot use per cu ft, and program accordingly. Using a hardness of 15 gpg, salt at 8 lbs/cu ft, and 60 GPPPD, I can set my days between regens at 9 and feel comfortable that I won't get hard water (unless I go over my 1-day reserve of 3600, or exceed my SFR, of course). In a perfect world, this would be just great.
But now let's say that instead of 60 GPPPD, I am using 40. I could either step down to 4 lbs of salt with the same days between regens, or I could up my days between to 14, and still be ok. But since we are on a clock, and have no idea of our usage, and don't update the programming accordingly, we are now wasting salt. About 12,000 grains per regen. (or days, if you consider we COULD HAVE gone 5 more days between regens) But if we were using a metered valve, that difference would be not be wasted since the computer knows we had that extra 12,000 grains based on lower gallons used per day, correct?
Using the clocked 9/60 numbers, one would expend 487 lbs of salt per year, and using the same settings, but having the computer change it automatically to 14/40, one would consume 317 lbs of salt per year, or 160# less. Seems a bit more efficient in my book; wouldn't you agree?