You have limited choices, you ...

You have limited choices, you can precipitate it (lime or some other chemistry) or you can oxidize it and filter it (more chemicals). All removal options produce a waste that needs to be dealt with. If you look into IX or electro/capacitive DI you still have a waste stream to deal with with a concentrated mineral content. The IX/Cap-DI will also give you a bunch of other inorganic components to deal with as will precipitation. No easy answer.