We are moving into a new house on a well and septic system. We had the water tested prior to closing and these are the results:

Iron: 0.17 mg/l
Magnesium : 28.2 mg/l
Potassium: 3.5 mg/l
Sodium: 116 mg/l
Fluoride: 2.94 mg/l
Hardness: 217 mg/l (12.7 gpg)
pH: 7.6
Total Dissolved Solids: 604 mg/l
Neg Bacteria
Neg Coliforms

Pump delivers approx 10 gpm with a 3/4" feed into the house.

There is an approx 12yo unbranded softener in the house. This probably needs to be replaced soon although the well inspector tested it and said there is soft water at the faucets. The whole house is on the softener and I plan on splitting out the cold kitchen sink and icemaker. I am looking for any suggestions on proper sizing and any recommendations. There is just 2 of us unless the kids come home. The home has 3.5 baths.

From the information I have found on this forum some call for a 3.5 cu ft softener primarily due to the higher magnesium level. According to my calculations I have a compensated hardness level of 70 gpg.

What do you suggest?

Thanks
Jeff