So you're old enough to check the basement and find out where the water comes in. If you were ten and scared of the basement, like I was at that age, I could understand that.
Adding calcium will no doubt help but all that sodium is not good for the snails, I believe. Find out if the hose is well water only. It's not rocket science. They're just big tanks with pipes coming in and pipes coming out, that are not hot water tanks. Usually near where the hot water tank is, or where the water pipe enters the house.
Even if the basement is totally finished, you should still be able to not only find the softener, it might be in a closet or behind a barrier, but once you find it, should not be too hard to figure out where the intake pipe is, and whether the intake pipe has any other pipe leading from it before it attaches to the water softener. If it does, you are good, that will be the the pipe going to the hose tap.