Low PH

The cyanuric acid in the pool is 70. It's 0 in the city water. We've used the trichlor tabs all summer. Water has been and still is crystal clear. I'll add the Borax tomorrow. I added a box last week with no change in results. Should I check the PH after adding each box? Thanks.

Yes, you should test pH after an hour or so.

It's important to understand that, with most color based pH tests including phenol red, the low end and high end of the test do NOT mean that the pH is at that level. Instead, it means the pH is at that level OR beyond. A pH reading of 6.8 means "6.8 or lower" and NOT "6.8 exactly".

So . . . your previous box of borax DID do something: it told you that your pH was NOT equal to 6.8, but that it was somewhere below that, possibly MUCH below. If it had been 6.8 exactly, you would have seen an increase.

I put the 3rd box of borax in 4 hours ago. The PH is now between 7.6 and 7.8. The chlorine seems a little lighter but is still bright orange. When I start to add chlorine after it's in the correct range, should I use bleach instead of the skimmer tabs? and can you tell me how much? I'm going to peruse your site now to see how to use the 3 B's. Continual thanks!!