Excuse the length of this post but I thought it best to include as much info as possible.
My pool was finished Apr 12, 2013. (My signature block contains the pertinent data about the install.) I followed my installer's suggestion and bought a Taylor K-2006 test kit. Monitoring my pool chemistry during the first season allowed me to get a "feel" for the way it will react in the full sun, hot, southern AZ summers.
We have a light swimmer load (my wife and I swim 2-3 times per week). Last season I noticed the FC levels always were a bit "high" (6-8 ppm) and I was using a lot of the Frog BacPacs (Trichlor)ľabout 1 every 2 weeks versus what the manufacturer stated "normal" use isľabout 1 every 3-4 weeks. Additionally, my pH was always rising towards 8.0 each weekly test. I could never get it to stay down into the 7.4-7.8 range for more than a few days. The TA averaged 100 ppm all season. The CH hovered around 300 ppm all season also (Pretty common for the hard water here in Tucson). I tested the CYA value 1 week after the initial fill and it was high: 90-100. However, the water appeared clear and thought nothing of the CYA number.
Towards the end of last season (Oct) I had a small green algae bloom. I was able to treat it via a dichlor shock treatment with aggressive brushing and filter cleaning. But as temps cooled off I was still using lots of Frog BacPacs and the FC kept going higher (8-10 ppm) even after setting the Frog Inline Chlorinator to its minimum setting. After research and contacting King Technologies, I discovered the pool builder installed the Frog system on the wrong side of the return. They had placed it on the in-floor cleaner side of the return where it was getting too much pressure. This was causing the BacPac to be used up twice as fast as normal and put too much chlorine in the pool. This plumbing error was repaired in Oct 2013. Following the repair, I got the FC stabilized to 2-4 ppm but the pH continued to stay high (7.9-8.1) and resisted weekly muriatic acid treatments.
As the weather has begun to warm, I am trying to get the pool back in great shape. I tested the water with my K-2006 kit with these results:
Water Temp- 70║F
Other than the FC and CYA, I know the other numbers are close to desired ranges. Due to the calibration marks on the Taylor CYA turbidity test, I couldn't accurately assess how high the CYA is. I took samples to two pool stores to see if they could give me a better idea. They estimated my CYA value at 120-150.
My questions are:
1) Is there an accurate CYA test for values above 100? I need to know how much water to remove/replace in my pool.
2) Could the introduction of "excess" trichlor from the Frog PacPacs caused the high CYA value in one season?
3) Could the ozone injector cause pH rise due to "aeration effects"?
4) Can the in-floor cleaner cause pH rise due to "aeration effects"?
BTW, this forum is a wealth of knowledge and should be the first stop for ANY pool owner! Any help with my issues/questions will be greatly appreciated.