waterbear, thanks for your comments. This is all new to me, and so a big experiment.
Testing daily and still waiting for change. Salt usage should drop as I am reducing the recharge intervals. Still not sure if gpg will increase or not. I turned off the clock based charge, and the regeneration is now based on usage only. I started at 600 gallons, and now down to 400 gallons before recharge. It may take a few more days before I see it recharge. Test results still showing 17ppm.
Peat moss works to lower CH, but not an easy (or wallet friendly) method. If I can safely raise the CH using soft water, that is my goal. So, I'm waiting to see what, if any, fine tuning I can do with my water softener can achieve.
Hot tub arrives next week, so I'm collecting as much information as I can before it arrives.