PH Problem

I suppose we should address a few things:
- Adding BS to address the low TA was the right thing to do. A TA of 20 was way too low.
- The erratic behavior between increasing the TA from 20 to other things like FC and pH are probably a coincidence. Increasing the TA should have no bearing on FC. The pH may have only been allowed to stay as low as you had it on the spreadsheet because the TA was too low. With a salt pool, you can expect the pH to remain more constant in the upper 7s (7.7-7.8).
- Your Poolmath has no real history, so you might want to start loading your info in there as well. I have a separate spreadsheet for my own personal notes, but I still load all of my tests in PoolMath.
- Neither your spreadsheet or Poolmath seem to show a CYA, so we have no idea where your FC "should" be according to the FC/CYA Levels. With a SWG we could assume your CYA is 70, but you should list it. What you consider to be high may actually not be high at all. In fact, if you had inclement weather and cloud cover, your FC can increase ffom the UV protection. Mine has recently.

So at this point I would recommend you let the pH rise and settle around 7.7-7.8. The TA of 50-60 should allow for that. The FC and CYA are a separate matter, but continue to ensure the FC is balanced to your CYA as noted on the FC/CYA Levels. Of course if an FC is allowed to exceed 10 ppm, it can then influence the pH reading, but I don't think you're at those numbers yet.

Gotcha! About the CYA. A min 70 is ideal for many of us SWG owners in the summer. The FC needs that protection. Not sure if you typically close your pool each winter, but you may not need to go all the way to 70 right now if things are cooling off a bit. A CYA of 50 or so might be enough for now with cooler weather and sun angles changing. So just play that by ear depending on how your FC is holding. You can evaluate things and always add more later if needed.