pH Rising and Testing

[TarheelFan]

I got my K-2006C test kit yesterday and have been doing some testing to try to get my levels normalized. I have them at pretty good levels:

FC - 5.5
CC - 0.0
pH - 7.7
TA - 120
CH - 70
CYA - 20

I am in the process of adding CYA via trichlor pucks that I was given by my pool installer and my pool is a vinyl AGP, so CH is not an issue for me. I overshot my FC target tonight because I trusted a test strip's reading that I had less than 1 FC so I over dosed slightly, but I expect the sun will bring the pool back under 5 by the time my kids get out of school and want to play in the pool.

My real questions are about pH. This morning, my pH tested at 7.4. That was the same as it tested the day before. I have added nothing to the pool other than Chlorine (2 trichlor pucks in a floater that did not dissolve more than 20% + 3 1/2 quarts of 6% bleach). We did have 4 kids + me splashing around in the pool for a couple of hours + I was relaxing in the pool for an hour on my own and found that if I squeezed one of those water balls that it makes lots of small bubbles, so I "aerated" the pool with that ball for about 30 minutes while I relaxed. My goal has been to raise my pH via aeration so that I could lower my TA just a bit, but I did not expect it to rise so much today. Is it reasonable to think that the kids and I could have aerated the pool enough to raise it .3? If that is all it takes, I should have no problem moving my TA over the next week or two. How much chlorine does it take to skew a pH test using the good test kit?

Also, will the pH lowering effect of trichlor pucks also lower TA or do I need to add acid to lower? I hope to get my pool to around 7.5 or 7.6 when I am done, as my eyes seem to burn with pH 7.8+ and my daughter's eyes seem to burn with pH under 7.4. Also, my tap/fill water's pH is 7.6 so I think getting it there would make things simple for when I refill the pool. Am I correct in thinking that I should lower TA if I want to normalize around 7.6?

 

[JasonLion]

Yes, some kids splashing really could raise the PH noticeably. The rate at which the PH goes up will slow down as the TA gets lower.

Trichlor will lower TA a little, but only slowly.

You may not be able to stabilize the PH as low as 7.6, though you can come fairly close.

 

[TarheelFan]

n/m....re-read your reply. guess the sun has gotten to my head today.


Thanks for the quick response.

 

[TarheelFan]

Interesting twist...

This morning my FC had dropped to 5.0 (lost .5 overnight?) but more importantly, my pH is back down to 7.4.

In trying to understand this, I read that Bleach is basic when added and acidic when consumed. So maybe adding Bleach last night raised my pH temporarily? Does that sound reasonable? Still trying to understand all of this so that I do not make any big mistakes by adding stuff too soon. Thanks in advance.

 

[duraleigh]

So maybe adding Bleach last night raised my pH temporarily?

The net effect of Bleach on pH is neutral. Any increase you may see is more than likely not mixed as well as it should be but the important thing to take away is that bleach has almost no affect on ph.

 

[TarheelFan]

I had read that fact (Bleach is pH neutral over time), which is why I am trying to understand my test results last night and this morning so that I do not over-react to any results in the future.

I had read that I should test pH prior to adding bleach (although I think that suggestion was made in response to the effects of high Chlorine levels on the pH test). Is this another case where I should read pH prior to adding Chlorine so that my test results are not skewed by the short term pH increase or is there something else going on here? Is the level of Chlorine that can impact a pH test different for different CYA levels?

When I do my tests tonight I will test pH prior to adding any Chlorine, but in the meantime, any information you guys can share is much appreciated.