Cursing...yup that'll work! Just kidding.
I'd bet just about anything you have no stabilizer in your pool and the sun's UV rays--even stronger in South Texas than in North Central New Jersey--are breaking down your chlorine within as little at 15 minutes.
Stabilizer, aka, CYA or Cyanuric Acid, or Isocyanuric Acid, or Conditioner is like sun screen for your chlorine. You need it to protect the chlorine from the UV rays, and you need it to be at least 30ppm in your pool. UNFORTUNATELY, your test kit (which is fine), called an OTO test kit, doesn't test for CYA. For that you need a kit that does.
We recommend two: The Taylor Technology K-2006 or K-2006C, available only on-line, but is a bit cheaper if you click on the link in Watermom's or PoolDoc's signature is the best (The "C" has larger bottles of the chemicals). But the cheaper and more readily available is the HTH 6-way drop kit, exclusively available at WalMart. The difference, primarily is the K-2006 has a far better chlorine test (the "FAS-DPD" test) and the HTH uses the same OTO test you have, only going to 5ppm rather than 3ppm. But both test CYA levels.
What you CAN do, is go to a pool store with a water sample and ask them to test it. Don't buy anything yet, but post the test results here. Under NO circumstances let them talk you into buying calcium (vinyl pools don't need it) algaecides (most have ammonia or copper--very bad) or anything else. You may need to buy CYA--but you can do that after we see the numbers.
Bookmarks