Re: Some closure
Fleck 5600SE, 1.0 cuft of C-249 resin, with tank jacket, and a stainless steel by pass valve.
The unit is programmed to recharge every 1200 gallons. For me and my girlfriend, it took us 8 days to use 1200 gallons.
Taking what you say literally, 1200 gallons, and that you have 24 gpg hardness, and you wanted to size for a family of 4 although there are only two of you now, then 1 cuft is too small and it isn't programmed correctly. IF it actually regenerated at 0 gallons remaining plus waiting until the next 2 AM, it is not going to continue giving you softened water for very long.
You used 23K of capacity, and 23k in a 1.0 cuft means your salt efficiency is fairly poor, with only two people there... What capacity is it set for and how many pounds of salt for the salt dose?