Quote Originally Posted by CarlD View Post
If they are the type wrapped in plastic like a capsule, and you throw the capsule away when it's empty, supposedly they work well.

If they are the type that looks like a caplet, save your money--they turn to mush in 6-8 hours and clog your skimmer--that's personal experience talking. They are pure garbage and do NOT work as advertised. I tried it. I know.
I just read learned about it yesterday so I am not sure which kind but I will certainly stay away from the "caplet" variety. I need a non-stabilized puck (I like to keep my CYA level under 20) and my CH is not a problem so the calcium based product seems like a good idea for vacation time.