1. I hope you got the K-2006 FAS-DPD (listed at $85 for the K-2006A) and not the K-2005 (listed at $70 for the K2005A). If not, you'll need to order the K-1515.

2. The HTH is a re-labeled Taylor, with an OTO / phenol red block. Unlike the DPD color match in the K2005, OTO provides a reliable and inexpensive way to QUICKLY test the water. So, it's helpful to have both.

3. The complete metal stain removal process is here: http://www.poolforum.com/pf2/showthread.php?7923
Please note that NONE of the steps are optional, so far as we know. Also, the process MUST proceed in the order described; do it out of order and you are likely to waste both your time and your money. Order links for the products needed are present on that page. If you choose NOT to use those order links, you must be VERY careful, particularly with the HEDP. Other liquid stain and scale product have different ingredients, and are NOT adequate substitutes.

4. I'm not going to put much effort into working out your test results, till you have some version of the Taylor. We see too many bogus 'guess-strip' results to be willing to trust them. The pH test is usually not too bad, and the chlorine test is about as accurate as OTO testing, but with a narrower range. CH and TA testing can be pretty bad, and CYA results are often random.

But it looks like things are generally moving in a positive direction, and that your high TA is responding to keeping the pH low.