Of course you are right, Carl, there were over 180 different types of alloys in the stainless steel group in 2001 and some are described in this EPA PDF file. You have to use the right stainless steel for the application. My point was only that pools with more salt in them may require stronger materials and that this is something that is not currently being said by the SWG folks. Instead, the claim appears to be that there is insignificant corrosion with the implication that the same materials can be used and one can expect the same lifetime of such materials. This just doesn't seem to fit all the facts and I want to know the real truth.

So this thread will hopefully sort all of this out with some hard data, from studies, good analysis, and from users experiences. That's how we got to those other gems of insight such as the chlorine/CYA relationship, first discovered through experience by Ben and then more finely honed through analysis of the chemistry by me, the explanation (after chlorine usage) of chlorinating liquid and bleach being fairly pH neutral while Dichlor lowered pH, and the techniques of lowering TA to reduce the rise in pH from carbon dioxide outgassing and (from Evan) the use of Borates to further reduce the pH rise in SWG pools, plus all the other important information about metal stains, test kit intereferences, sheet method for dilution, and the like from all the great contributors to this forum including yourself.

Richard