OK, so I got a pond kit to test my bond.
I read it as the ph level was too high and the total buffering
capacity was too low. According to the instructions I have to add
Sodium Bicarbonate (baking soda) to bring it up.

My question is, is the standard baking soda in the grocery store ok to
use as long as I just get pure baking soda? If so how much should I
add?
My pond is about 2000 gallons.

Thanks for the info.