Natron

[Baxter]

You can buy Natron, it's not too expensive (~1k).

I do, however, agree concerning the ingredients :I Muddy Water, Mineral Water, Distilled Water, Effervescent Water... seems a little like overkill.

I just think 1k is too pricey for such a common ingredient for many crafts. I wouldn't mind they keep the price 1k, and keep the ingredient effervescent if they just changed it back to 6 per. The water is a bit of a hassle.