What is going on?

[CarlD]

Washing Soda is chemically the same as pH Up! (and, yes, it does raise both pH and T/A)

Baking Soda is chemically the same as Total Alkalinity Increaser (guess what IT does!)

Borax is Borax. It just raises pH, not T/A.

Now, here's the rub: When you raise pH your MEASURED T/A rises, and when you lower pH, it falls. pH and T/A are related and connected.

The ONLY way to raise pH without raising T/A is by aeration--aerating your pool water with waterfalls, fountains, gangs of wild 12 year olds (Wait--wild and 12 year olds is redundant), etc.

But when you use Washing Soda or Baking soda, the T/A rises MORE than the variation caused by the change in pH, which is why we say they increase T/A.

Hope this helps.

[Watermom]

Carl has given you good information, like usual. To add to that, you're actually ok with alk at 80 and ph of 7.2 right where they are, but you don't really want them any lower. Also, I don't think you have CC of 15. More likely FC or TC of 15.