Have the programing guide for the SE? let me know if you don't.
here is How I would do the programing with your 2 people and 15 grains.
12 minute backwash
60 minute brine/rinse
6 minute rapid rinse
6 minutes at .5gpm to give 9 lbs.
meter for 1800 gallons
day defalt if wish.. 18 days.
if there is a salt plate at the bottom then water about 2-3 inches above the plate, if no plate the about 6 inches.