You don't list a pH reading, so I don't know whether it needs to come down or not. Since you've been using so much stabilized chlorine, though, I doubt it needs to be lowered. Chances are it needs to be raised. Can you test for that and list your result?

The next thing I would do is to test your chlorine level tonight, after the sun is off the pool, and test it again in the morning, before the sun hits the pool. Compare those readings, and if there's more than 1 ppm difference, then you need to shock the pool, which for a CYA =50 means you need to raise the chlorine to 15-18 ppm and hold it there until the water clears up and until you can run that test overnight again without losing any chlorine. If there is less than 1 ppm difference, then you need to keep your filter running and be a little patient to allow the filter to remove any junk from the water.

Do yourself a favor and get your own test kit and test your water yourself. Pool store test results are sometimes reliable and sometimes not, but there's no real way to know until you have water problems. We highly recommend the K-2006 linked in my sig, but for now, at least go to WalMart and get either the hth 6-way drop kit or the cheapie OTO kit (uses yellow and red drops for chlorine and pH) and use that. To determine chlorine demand overnight, you have to be able to get accurate testing done at specific times, and the pool store just won't be able to do that for you.


Janet