What happens to tomato plants watered with water that goes through a water softener first?
Any kind of water I’ve used, iron water, lime water, softened water, etc., eventually seems to screw up the soil and growth of the plant.
It might still give the boost to the tomatoes they are talking about because of the minerals in it. With all the trace mineral fertilizers out there I myself wouldn’t risk mineraled or salt water destroying the soil.