If you want to save some money, you can use this.https://www.amazon.com/dp/B079P7QCJF/ref=sspa_dk_hqp_detail_aax_0?psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyUUJQS09OOVlNMUpWJmVuY3J5cHRlZElkPUEwMTk3NzI3MTFINUtGSlVQUlg3NCZlbmNyeXB0ZWRBZElkPUEwMDgwMjE3S085SEJEVVFKU1hHJndpZGdldE5hbWU9c3BfaHFwX3NoYXJlZCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU= You can go to you tube and search Kevin Novaks videos where he explains using this product to make his DYI "Chemipure"
Water Softener Resin Media Replacement 100% Ion Exchange Cation - 0.25 CuFt https://www.amazon.com/dp/B079P7QCJF/ref=cm_sw_r_awdo_navT_a_862A1RZ2ARTE9K4M8HXV