Borax To Raise Ph

[pittsburgh1328]

How much Borax would I need to raise my pH from 7.0 to the ideal range? I have a 10,500 gallon vinyl above ground.

Thank you.

[chem geek]

You also asked this on this thread on poolcenter.com. In case no one answers you there, here is my answer.

It depends on your TA level. If your TA is at 100, then in your 10,500 gallon pool it would take 73.7 ounces weight (about 8.8 cups) or nearly one box of 20 Mule Team Borax (one box is 76 ounces weight).

If your TA is already high and you want to lower it, then just aerate the water to raise the pH since that will do so without any change in Total Alkalinity (TA).

[pittsburgh1328]

Does Borax increase my TA as well? When I test TA on the Taylor K-2006 test kit my TA is 80, I think. When you use the taylor kit it tells you to add the reagent until it turn from green to red. When it turns pink and does not swirl back to green--is that the "red" they are referring to??

[chem geek]

Any change in pH due to acid or base will also change TA. So a rise in pH from Borax will also raise the TA. In addition, Borax raises the TA by a small and usually not measurable additional amount. It certainly raises the TA by far less (about half) the amount that using pH Up (sodium carbonate / soda ash / washing soda) does and Borax adds no carbonates. A more pure base for raising pH is sodium hydroxide / lye / caustic soda but that is not normally used (though certainly can be).

For drop tests where color changes, the "end" is the last drop that causes a color change. If you add another drop and there is no change, then the previous drop is the "last" one to be counted. So yes, if you add a drop and it turns pink and does not go back to green, then you are close and that *may* be the last drop. If you add another drop and the color does not change, then it was indeed the last drop, but if the color changes some more (gets noticeably more red), then this drop should also be counted (and another drop should not cause any more color change). The test is only accurate to within 1 drop anyway so consistency is more important.