red_foreman wrote:
Question: would a buffer of sodium carbonate(baking soda) help keep the
swings to a minimal??

I used to add a bit of baking soda to my CO2 injected planted tank and
it worked great. Baking soda sets up a bit of extra carbonate buffering
which lessens the pH swings. I think I added a total of about a
teaspoon to my 29 gallon tank, over a few days. If you add too much, it
will raise the overall pH of the tank so keep monitoring it and add very
gradually. Like any salt, you will have to add more with water changes.

Elaine