Brace yourself for a trip down the rabbit hole my friend and take your Chem 101 recall with you! There is a ton of material on the web and in the forums, like BF, on water chemistry. The one that gave me a fair idea of what I should try to understand was the 3 part series on water that Jamil Zainacheff (sp?) did with John Palmer on The Brewing Network's Brew Strong Podcast. http://www.thebrewingnetwork.com/shows/brewstrong/ I think I listened to it about 4 times before I really started to grasp it. Palmer's a dry speaker to me; maybe that's why. The one thing that I took from it was that my well water, given its qualities and not trying to alter it, is best for dark beers...a perfect fit for my palate!