If your softener has been using less than 15 lbs of softener salt per cuft of resin per regeneration, you get the maximum K of capacity of 30K per regeneration. It is a very rare softener that is programmed that way.
Most are programmed to use much less salt than 15 lbs/cuft of resin so.. you don't get the maximum K of capacity meaning not all the resin is regenerated, just the amount of capacity you use based on the hardness and number of people using water on a daily basis. IF you have used more capacity than the softener has been programmed for, yuo get hard water through the softener.
Example... you have a 1 cuft (32K as they are called although you don't get more than 30K/cuft) and it is programmed for 6 lbs of salt per cuft which regenerates 20K, leaving 10K of the original K of capacity still in the resin/softener.
So some day you use more than 20K of capacity by say 3K. Only 20K is regenerated the next regen, leaving 7K.
Now do that overuse a number of times (like your drip irrigation) and you use up the 'extra' K of new resin capacity and then your 6 lbs can't regenerate the 20K the softener uses between regenerations based on metered gallons, and you get hard water through the softener and start looking for why that is.... and find nothing wrong with the softener's operation.
To cure that situation you need to change the salt dose to 15lbs and do 2 manual regenerations one right after the other with no water use during or between the two so you regenerate all the resin back to 30K/cuft. Then change the salt dose back to the 6lbs or whatever is was originally and don't run irrigation water through the softener anymore.
You use potassium chloride and should increase the salt dose by 12-30% to equal the capacity that that much less sodium chloride would require for the same K of capacity. Or, my suggestion is to switch to salt and save some money over buying expensive potassium chloride.
Holy Cow Gary, thank you so very much for the explanation but I'm only a month new to water softeners and don't understand most of what you said. Sorry to be a dumb%$#. Is there a softener for dummies book?
I'm using potassium since the softener goes to the backyard to water plants that are not on the drip system. The drip has been off for a week so no water has been used for it.
The only setting I have on the softener are are the salt level and hardness.
The tank level gauge goes from 1-8 and it was at 6.5 before the regeneration and that's what I had the salt level programmed at and my hardness per the city's website is 12 and I bumped it up to 19 for Iron but the Tucson water test results didn't have the word "Iron" in it but I raised the level just for the heck of it in case there's some Iron in the water.
It's a 32k grain softener and it did it's brine cycle for almost an hour last night and the total process took about 2hrs. Don't know if that tells anything.
Here's what the softener specs say
Rated capacity 15,300 gains with 3lbs of salt, 32,800 grains with 9.6lbs of salt, and 39,100 grains with 16.1lbs of salt
Rated efficiency 5,100 grains/lb @ 3lbs of salt
Amount of high capacity resin 52.5/1.01
I have no idea what that means.