I recently moved into a house with a whole-house salt-based softener and it just about killed every plant in the tank. I'd never had such a system and I didn't know how they worked. It took me a while to figure out that the external faucets are not on the softener, so you might try yours and see. I installed an RO filter to deal with the unsoftened water. I'm still futzing with the mix between RO and unsoftened faucet to get the best results.