A pound of epsom salt is depleted per float?

I was surfing the FloatOn facebook page and noticed this:

My reactins to this post:

1. I need to dump a 6 pound bag of epsom salt in the tank after every 6 floats.
2. I do not agree about the need to add more water… at least not directly. Because I dose the tank with H2O2 perhaps that is why I dont notice any water depletion… even after months of daily floating. In fact, there was a recent thread where a number of professional centers dont change their water for years at a time.
3. Water would only evaporate if heated to 100 degrees of more. Perhaps they have a heater in their plumbing system that evaporates water? I don’t know.