I have been told by posters that I can buy bulk food grade citric acid (also called Sour Salt, although that version comes in large crystals) to decalcify my Gaggia Classic. I still need more info though, apart from the difficulty I am having finding it in any supermarket.

1) Are there different concentrations, and are the sour salt crystals of a different concentration than the citric acid?

2) How much should I use (of each type, if you know) for 1 tank of water (or per how much water?)

Thanks in advance for any replies....

It's usually not carried in supermarkets, except Indian ones; try home brewing or soap/cosmetics making supplies vendors on the web.

2 tablespoons per liter is roughly the strength of regular lemon juice (try a sip). For the Gaggia, use about 1 to 1.5 table spoons per liter.

i bought my bulk citric acid from a natural foods market. in your area, try whole foods or any market that sells bulk herbs (for homeopathic medicine). its very cheap too. hope this helps, and good luck.

If you can't find locally,
Citric Acid @ AmericanSpice.com

Citric acid salts are also carried by most pharmacies.

Just for information,
Pharmacy for 14oz. $14.95, Home Brewer supplier: 1# $3.75
-Richard