I was wondering about this. I know all the stories of floating in the Dead Sea, but the salinity there is a mind-boggling 330,000 ppm, it must be almost like slurry. I had thought that maybe 3500 ppm was so low, that I'd not even notice the difference.I've been the only one to notice the taste at 3400, but we haven't had a wide variety of users, either. I joke about it, but it really is significant how much better I can float! Literally no air mattress needed! It's become one of the favorite things to do - just be a dead body, lying face up on the surface of the water, watching planes and clouds go by overhead.
We are very used to swimming in the Atlantic ocean, and I've read that holds around 30,000 ppm. My pool salinity prior to adding salt was 600 ppm, so there was always some salt there, I only increased it from 0.06% to 0.33%.
Like Turbo said, I'm hoping it's just the shock of the abrupt change, and that they'll soon forget about it.