Not sure if this is an option for you, but we installed a water descaler. Seems to be working and mineral buildup pretty much went away. Was cheaper and no maintenance. Was easily enough to put in by ourselves.
Capacitive Electronic Water Descaler System - Alternative Water Softener Salt Free for Whole House, Reduces the effects of Limescale and Rust formation [CWD24, Max 1" Pipe] https://www.amazon.com/dp/B07X7XYKRB/ref=cm_sw_r_cp_api_glt_fabc_TRY4X2GKGNKF3FVB6C24