yesterday we went to the pool shop and bought "ph minus". it consists of "sodium bisulphate", what is this? i was expecting muriatic acid, but they didnt have this.
we visited the chemistry shop and bought some chemicals, soda ash etc. we also found this:
calcium chloride, it says 74% min. flake. is that ok for getting the calcium up? is is a powder that one must be careful with, or is it safe? i need to add like 10kg (my CH level is 90).