You can add a filter to your main water line that filters for the whole house, usually restaurants/big companys use them but they are not that expensive just require filter being changed more often as more water is being used/needs to be filtered. https://www.amazon.com/Pentair-5600sxt-48k-10-Softener-Upgraded-Capacity/dp/B00YFOTWZG?ref_=fsclp_pl_dp_1
This is the one I got: https://www.amazon.com/gp/product/B00YFOTWZG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
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We installed it on our own.
Make sure your house has a 'salt water loop' so you don't accidentally salt your yard.