Ph really high and can’t get it down

[aggiejet]

Two days ago I tested water and Ph was 7.0, TA 90, CH 260 CYA 0

I followed the guidance provided by PoolMath (add 215 oz of Borax)

The Ph is very high now. I don’t know exactly how high it really is, as test kit stops at 8. Water sample is very red after adding test droplets. I am attempting a gradual draw down to normal Ph (to avoid a whipsaw back to too low) I have added two doses (about 70 oz) of 34.5 acid, and water is still above 8.0.

What have I done wrong and what should I do next?

 

[PoolGate]

Add more muriatic! Small doses.

 

[ajw22]

Assume your PH is 8 add the amout of MA PoolMath says. Repeat until you get a reading under 8.

Next time PH is low aerate your pool to raise PH. You are less likely to get it too high.

 

[aggiejet]

Assume your PH is 8 add the amout of MA PoolMath says. Repeat until you get a reading under 8.

Next time PH is low aerate your pool to raise PH. You are less likely to get it too high.

Great idea. I don’t know why I didn’t think of aeration. Thanks.

 

[SemperFly]

You have a Taylor K2006 kit? You could run an acid demand test and that would indicate how much acid you'd need to add to get to a specific target.

 

[Richard320]

Two thoughts:
1) Is the FC really high? Because if it's over 10, it can cause pH to read falsely high.
2) Is your pool perhaps smaller than you think? This time you overshot on pH rise. Looking at your slender history, you had problems overshooting CH last year.