You should be able to pick up the Calcium Chloride from your local Pinch a Penny pool supply. Just call around and ask for Dowflake.
If you can get by with just dripping kalk, i would do that, if not, diy 2 part is pretty simple and cheap. You'll also be amazed how much cal/alk that sand bed can suck up as well as when your coraline starts growing....