The Gaggia decalcifier is used to rid espresso machines of scale build-up and it's also used for ridding your machine of calcium deposits.
Pros:
This product will lengthen the life of your machine and the taste of the coffee
cons:
It's not really clear as to how much water should be used - "just use the bottle and fill your reservoir" (but different machines have different size reservoirs sizes - so it does leave you wondering how much to use)
However, followed the directions as per the bottle and it seems to clean pretty well.
