I suppose I should mention this for those reading.
If you have apple snails or catfish in your tank, Don't pour the salt down over top of them where they are forced to walk in it.
Just go off away's from them and then pour it in, They won't walk in it until it's dissolved.
One time when I accidentally poured it in over one of my applesnails, Poor little guy kept raising up on his front as if walking on hot coals, I swear I could almost hear him cry out each time,
I reached in and moved him off aways from it..
just thought I should clear that up...