Hello,
The only probable solution would be to use IPA(Isopopryl Alcohol), this as a freezing point of around 89degrees, not sure wether this is fahrenheit or celsius.
But when mixed with water about a coke can full with 250ltrs approx, it should help.
It won't stop water from freezing, but will increase the time it takes for water to freeze.
Also IPA does not affect the TDS of pure water.
I hope this has helped.
Kind regards.