Low PH

[Jeton]

As per your request I just tested the swimming pool and our city water using the new HTH 6-Way: Swimming Pool: Alkalinity 60, Hardness 0 (the drops did not turn the water red at all), CA 70, PH 6.8 and Chlorine dark orange. We didn't get the distilled water so we couldn't test the PH using it. City water results: Alkalinity 100, Hardness 170, CA 0, PH 7.2 and Chlorine .5 or less. There have been no chlorine tablets in the skimmer for about 36 hours and the test results are the same!

[PoolDoc]

I'm inclined to think your pH is low -- so go back to Walmart and get about 10 boxes of 20 Mule Team Borax + some distilled water. Go ahead and start adding borax, 1 box at a time, added slowly to the skimmer. BUT also use the distilled water to test your pH level.

And, check your pH test by adding a few grains of borax to the pH sample AFTER you've added the phenol red and taken a reading. The color should change to near purple.

Low pH is NOT good for vinyl liners, or for pool heaters, so get right on this.

I'm puzzled by the readings -- you've been using trichlor tabs all summer? And, you haven't had any algae or slime? In that case, I understand how your pH could be low, but I don't understand how you could have 0.0 cyanuric acid (CYA).

[Jeton]

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.

[PoolDoc]

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.

[Jeton]

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!!