Amounts of Boxax, Baking soda?

I have a 13,000 AG pool. How much Boxax and Baking soda should I add?

Hi jenwilli, welcome to the forum!

As for how much to add, that depends on what your current pool water numbers are and what you want them to be. The baking soda will primarily raise your Total Alkalinity (TA), but will also slightly raise your pH as well. The Borax will raise your pH with only a small rise in TA.

So, you gave us your pool volume, but we need to know what pH and TA you are starting with and what you want to end up with. It would be also useful to know your Cyanuric Acid (CYA) level since that will also have some pH buffering effect. And for completeness, though it won't affect pH nor TA, it would be nice to know your Calcium Hardness (CH) level as well and whether you are using a plaster/grout/gunite pool or a vinyl/fiberglass pool and finally what your Free Chlorine (FC) and Total Chlorine (TC) levels are (and whether you use a salt water chlorine generator or add chlorine manually and if so, what kind of chlorine -- liquid chlorinating liquid, bleach, or Tri-Chlor tablets).

For most calculations, except for how much Borax to add for a pH change, you can use BleachCalc found in a link at the following post.

Richard