In reply to thewilliams1, filters will not stop your machine from scaling, ion exchange (water softener) is the only way to remove calcium. Frankly, "heavy metals" filters is a gimmick. There is only one way to remove 99.9999% of toxins and heavy metals, and that's RO.
Many folks need to us RO...
Test Your Water
TDS is not just your mineral content, but may include heavy metals and sodium. All households, no matter the water source should have RO systems. a Mineral + cartridge will add the good minerals back in. Where I live we have some of the highest quality municipal water supplies...