New pool installed in December, salt water/gunite, and new owner as well. ph is 7.6, Cl is 2.0 and TA is 100. Just recently I have noticed water marks on tile and stone, white marks marking the top line of the water and on the water fall. For a long time, our Cl level was really high and I never noticed the stains. Now that the Cl level is in range(??), I have noticed staining. Is there something wrong with my chemistry or should I be doing something different? I can send water samples to my pool contractor and they keep telling me that my levels are all low, especially my TA. I've been using the pool calculator and I thought I was on the right path. Any/all help would be greatly appreciated!