Ok. Using the liquid chlorine from the pool store is great--I wish Louisiana would get caught up with everybody else and make it legal for stores to carry it here!!

You can ignore the bromine reading if you haven't added any to your pool--just pay attention to the chlorine side. I'm assuming you're using an OTO test for chlorine and pH--maybe the 5-way kit from WalMart? If so, that'll work great for now. pH is good, alk is good. You can leave off the calcium chloride, because the calcium does not matter in a vinyl pool, as long as you have "some". 130 is fine.

In order to keep chlorine in the pool, you need some cyanuric acid....is it possible that you cleaned the filter right after you added the CYA last year? If so, it all probably just washed out, because it can take up to 4-6 days for it to dissolve and show up on test results. I would suggest that you shoot for 30-40 ppm, added either through the skimmer very slowly and not tested for, backwashed, or more added, for a week....or you can put it in an old sock and hang it in front of the pool water return, and allow it to dissolve that way.

On to your question......my best guess would be tannins from the leaves and acorns that get into the pool during the winter as the cause for your yellowing. My deep end does that every winter, too, worse in the areas where the leaves congregate. If that's the problem, then getting the pool up to shock level (chlorine of 12-15 ppm with no stabilizer) and holding it there for a couple of days usually will resolve the problem. If not, then you can try crushing up a vitamin C tablet and rubbing it on one of the yellowed areas and see if that lifts the stain.

Janet