Another pH/TA Question

[kenmar]

Hi All,

Since my pool was installed a month ago, my pH/TA have been creeping up.
Everytime pH gets to about 7.8 I add some acid.
My gut feeling is that it should not be necessary to add gallons of acid during a season (I am on course for that)
Below is list of my test results and adjustments.
Any thoughts?

If had to guess, my CYA is too low.
My low CYA is causing me to add a lot of bleach.
Bleach has a high pH (and that is what is drivin up my pH)

Any help would be greatly appreciated.



-Ken-

http://s390.photobucket.com/albums/oo347/kmaritch/Pool/

 

[ideliver]

you are correct...raising your CYA to 40 MAY lower your FC loss to the sun...FWIW...I am going to raise my CYA to 50 in April to see if that cuts down on my FC loss...but I don't use a pool cover so it may not matter much either way....

Your addition of bleach does cause your pH to slowly rise...this is all normal and expected

 

[JasonLion]

Can you tell us what you are using to do the water testing with? Also, what brand of bleach are you using?

It doesn't seem likely that CYA fell from 32 to 22 in just a few days, and no CYA test is as precise as the numbers you have written down.

It is not uncommon for PH to rise slowly, but your TA shouldn't also be rising. Have you been adding any chemicals that aren't on the chart? Have you been adding water to top off the pool? If so, have you tested your fill water?

 

[kenmar]

Can you tell us what you are using to do the water testing with?
TF-100 Test Kit


Also, what brand of bleach are you using?
Clorox


It doesn't seem likely that CYA fell from 32 to 22 in just a few days..
The "blue" cells are actual measurements, in the white cells I just carry the previous value.


and no CYA test is as precise as the numbers you have written down.
Just a guestimate based upon the level of water in the fill tube.


Have you been adding any chemicals that aren't on the chart?
No


Have you been adding water to top off the pool?
No, but it has been raining a lot, in fact, I hav. been dumping water.

If so, have you tested your fill water?
Only rain has been added since the initial fill (I have not tested the rain )

 

[chem geek]

So rain aerates the water more and can help explain the pH rise. I'm at a loss for the TA rise unless that is from some evaporation and refill. What is the TA of your fill water? You didn't measure Calcium Hardness (CH) but if your fill water is also high in CH, then tracking it might show a correlation with TA and then you'd know that evaporation and refill are the sources for those two rising.