Should you use food grade salt instead of rock salt and why or why not?

Answer 1

Rock salt is not as pure. There is often foreign material left from when they scraped it up from the ground. Food grade salt is much cleaner and it includs iodine which is there to prevent thyroid problems. You can still get coarse salt that is considered "food grade". If you are using it to melt snow use the rock salt its cheaper and the larger grains give better traction