I have a Masterspa hot tub with a Balboa MS90U spa pack that I'm thinking of converting to salt. I spoke with Masterspa and they said their products have "not been tested with salt water" so it may void my warranty. Same with Balboa. Is this a serious concern or just the manufacturers just trying to cover themselves? The salt says it needs 1500 to 2000 ppm in order to operate and this seems like a fairly low level to be concerned about corrosion.