I wouldn't set it up that way for 2 people and 3 gpg of hardness with no iron. Eleven or 16 days is too long between regenerations and it's using too much salt and water.
I don't recall the size of the tanks but I would do a regeneration of each tank with the max lbs of salt for the cuft of resin (15 lbs/cuft) and then program it based on 120 * 3 = 360 * 8 = 3K (3000/3= 1000 gals - those used per regeneration rounded down to the lower 25 gallons )and say 3 lbs of salt.
If you have a 2.0 gpm DLFC, you can remove it and see if there is a 2.0 or what the number is on it, that's the gpm. You can use the math formula in the manual to come up with the exact number of gallons used per regeneration (minutes times the DLFC gpm), and subtract them from the meter setting and round them down to the nearest 25 gallons. You do that because your meter dial is marked in 25 gallon increments.
And if you do the math right to get the programming right, you don't have to make a change and then use water for a few weeks or a month to see how it goes.
It doesn't matter how many people show up, however many use up the gallons on the meter faster than just the two of you normally do. The guests leave and you go back up to the on average once a week regeneration per tank. The down side of that is that your control valve does not do a purge rinse of the week old stagnant water, and in TX fairly warm water in the stand by tank before putting it into service. Frankly unless your household is using softened water 24/7, you don't need a twin tank softener and would be better off with a regular softener regenerating at 2 AM once every 7-9 days.
Your 10" x 48" is probably a 10 x 47, a 1.25 cuft (40K) per tank. Or an undersized 1.5 cuft.
Thanks Gary,
But boy I am really confused now..Now I know what it was like trying to explain an auto repair to a not auto person
I followed your calculation, up until the 3000/3. I didn't see that on your page, is that something you did because of my unusual situation? where does the division by 3 come from? I figured this unit is overkill but it was free.
One thing I can't find any info on is the timings for backwash, Brine/rinse, Rapid rinse timing settings. Only the brine fill. How do you calculate the necessary timing for these other steps? If I am reading my dial correctly, this is what I see:
Backwash-8 minutes (purpose of this to remove sediment?)
Brine/Rinse-64 minutes (wow that seems long)(so this sucks the brine solution from the brine tank until the brine tank valve closes, at which time this cycle becomes the rinse?)
Rapid rinse-6 minutes
Brine fill-6 minutes, @.50 per minute, does this mean 3 gallons and 3 lbs of salt? (does this seem light? Did I read you think this should be set at 22.50 based on your 15lb per cf media? Won't this really raise my salt use?)
With my light load, do I need to have a 64 minute brine/rinse? Seems with my small salt draw, that maybe this brine rinse is too long? (tapping for water savings here)
In the first part of your reply you said not to use the 2 person, 3 grain settings because it would use too much water and salt? This I don't understand, it would appear to me to use less, but not flush often enough which seems to be my biggest problem here, correct? Water sitting in the unused tank too long?
Please forgive all the questions, I can't believe this is so hard for me to grasp. Throw a car repair at me, or a computer and I am good but this stuff it tough for me. Thank goodness for folks like you all, the rest of us would really screw it up!
I am just glad I didn't go in there and start re-arranging pins and timing without asking someone.
Second let me apologize for my long posts. I try to relay everything I thing pertinent but I am sure is exhausting to read.
Thanks,
John