That's great thanks for info, I can just not use my floating magnet, only thing I was worried about was I heard the magnetism parts in the sand are harmful to fish, I hope this stuff is a bit heavier then play sand because I do have fish that like to dash around and it will kick up a lot of sand!
I have used Unipac Limpopo before, that sand was just right not too light to be kicked up, was described as black sand but looked dark brown which was not good at all!