7000sxt. A 2.5 cubic ft softener will use a 13" tank, which is outside the spec of the 5600sxt.

Thank you, this is very helpful. Could you also provide feedback on whether I need 2 or 2.5 cu ft softener. The house is 4000 sq ft, 5 bathrooms, 4 people living, sometimes 5, wife likes to do laundry (3-4 times per week) and wash dishes by hand. Hardness 22-26, TDS 350, no iron, manganese. I was recommended 2 cu ft by local water expert and also 2.5 from another source. The goal is balance of conservative use of water and salt. Thank you again.

Asked and answered on your previous thread.

A little forum etiquette: Keep your posts about the same issue in the same thread so we don't have to bounce around to try and find the necessary information.