To ChemGeek & CarlD and WaterMom - Thank you sooooo much for your advice. It really makes sense and it is exactly the info I was looking for / hoping to confirm. My K-2006 kit has been shipped & I should receive this week.

Out of curiosity - since we are in Texas & due to the climate/extended pool season - would it be reasonable to consider using tri-chlor tabs in the summer and liquid bleach in the winter to help counteract rising CYA? And also out of curiosity, the Magenta Stuff -- if it helps prevent the stains from metals, what kind of residual stuff would be left over in the water & would it eventually dissipate like chlorine or would it stick around like other particles? And can testing the water somehow pick that stuff up? Just wondering since I know the pool installer dumped an entire container of the stuff in the pool within a week of the fill.