Thank you very much - I'll get started researching the links and doing homework today.

Up to now I've been getting testing done at the pool shop, a national retailer. It's always someone different and I've seen them make occasional mistakes before both with my own samples and other people's while I wait in line. Do I trust their analysis? I haven't a clue. Until I follow your advice and get my own testing gear I've got nothing to compare it with.

I've removed the 2 floaters with the 3" tabs. Let me know if that's not necessary.

I'll post with my findings - thanks again!
keith