i've asked questions at the gardenweb forum about my water conditioning needs and have run out of my allotment of free advice. the most recent analysis of my well water reveals 47 gpg hardness. 1.4 ppm iron. .26 ppm manganese. pH 7.51. TDS 1200 ppm or greater. another lab put the TDS at 1600 ppm. the iron is ferrous. no iron bacteria present. i intend to put a whole house 4" x 10" dual 75/25 micron filter before the softener. thought about an iron filter, but figured it is less expensive to re-bed any size softener i'd end up with, one or twice before i croak. i can get a Hellenbrand twin 1.0 cu.ft. or 2.0 cu.ft. single. even though these are proprietary, i'd prefer to stick with a Clack valving system. all of the online calculators, either suggest 64K, 80K and one suggests a 3.5 cu. ft. softener. there are two users, 3 out of 7 days 180 gallons of water is used and that is a max, probably way less. the remaining four days i'd figure 480 gallons. so, compensated hardness is say...55 gpg x 94 gallons per day = 5170 grains per day. the seller goes with 55 gpg x 150 gallons per day = 8250 grains per day. am i being undersized, for hardness and high TDS along with less than standard water usage? i have the capability to increase or decrease the amount of flow by changing the psi on a constant pressure water system. currently at 50 psi, drawing 12 gpm at an outside bib. 1 tub/shower, washer, kitchen sink and bath sink is all i have. my head is about to explode. please....any verification or homework you can point me to would be greatly appreciated. thanks, and good day.