My parents have a pool and I asked them to bring a water sample when they came down (2 hours away) for the weekend. The water sample was over 24 hours old so that may make the testing obsolete.
18 x 36 concrete pool painted with chlorinated rubber with fiberglass sides. DE filter (40ish years old). Maple trees surround the pool along with various trees around the subdivision. Using chlorinator with tri-chlor tabs to chlorinate and at times bags of shock.
That being said, here are his results:
PH: WITHIN RANGE
CYA: 80-100 (we both did the test and came up with separate results)
He is saying that if he doesn't keep his chlorine up, he starts to notice algae starting to grow. He then brushes it in order to remove the algae and bumps up his chlorine levels. Once the levels are higher, the algae doesn't appear. Due to the Maple trees surrounding the pool and constantly dropping in the skimmer, does the residue affect the water quality necessitating an aggressive algae regiment in order to counteract.
He's currently adding PhosFree Plus to counteract the organic material in the pool. This added once a week.
Let me know your thoughts and also keep in mind that the sample was tested over 24 hours with the TFP100.