stain or scale just won't go away

[PoolDoc]

Obviously, without seeing it, and without test results, we really can't tell anything.

Can you:
#1 - take pictures (mail them to poolforum AT gmail DOT com)
#2 - get the best test results available (dealer?)
#3 - get a Taylor K2006 or 2006C so we can get GOOD test results.
#4 - list the different chemicals you've used over the past 9 months (going back to the end of the summer 2010)

Unfortunately, I don't know what's in the Jacks Magic kit, so I don't know what you've tested. One test you might want to do is to put a bit of the scale into a covered glass half full of white vinegar and let it sit overnight, to see if it dissolves or not.

[jefftex]

Thanks PoolDoc. First thing I'll do is the scale test in some vinegar solution (acid) as you suggested. That is an easy test. I'm swamped at work. I'll post a pic in the next 2 days. It is tan colored. We pretty much had a perfect pool since it was resurfaced in 2004.