A bit confused

[Cal_Newbie]

Oh , one last thingy...my house water TA is 270ppm !!!!!!

Suggestions as to what to do when using the house water to fill with? Or is so diluted that I only need to add acid to adjust.

[chem geek]

If you want to avoid a slow but steady rise in Total Alklainity (TA) from your fill water, then I would suggest that you do the acid/aeration technique with your house water in a large container and then use that water to add to the pool to fill after evaporation. It is FAR easier to lower the TA of your fill water before getting it into the pool.

Of course, whether this is worth doing is a function of how much fill water you will be adding over time. If it's a small fraction of your pool water volume, then the above procedure is not worth it.

Richard

[Cal_Newbie]

When I do my bleach to shock the pool, this will give me a rise in pH, if I recall. Do I let the pH drift down or should I add acid? Friggin stuff...I breezed pharmacology, drip rates, med conversions in the middle of the night..thank goodness my patients are not pools...

[chem geek]

Bleach (and chlorinating liquid) do raise the pH when you add them, but the usage of the chlorine lowers the pH so it's really pH neutral. Don't try to add acid after adding bleach in order to get the pH just right. You'll yo-yo back and forth. Measure your pH consistently, just before you add more chlorine. Finally, if you have enough TA, the addition of chlorine will only raise the pH by about 0.1 to 0.2 which isn't very much. If you measure your pH before you add chlorine, you can target 7.4 and then after chlorine addition it will be 7.5-7.6 and will then slowly drift back down to 7.4 the next time you add chlorine.

The above scenario assumes you aren't experiencing a general rise in pH. Most pools have that and it has nothing to do with the chlorine, but rather the outgassing of carbon dioxide from your pool. Having a lower TA (say, 80 ppm) helps reduce this problem.

Richard