So I tried leaving my pool open and the pH still stayed pretty much the same. I then realized that I could use my pool cover pump that normally pumps water off of the pool cover and could attach its output hose to a portable plastic shower that I have and put the pump into the pool (it's a waterproof pump -- essentially like a sump pump). I had to take off the shower nozzle because it gave too much resistance to the water and shut down the pump, but with the nozzle off I was in business. The stream of water hitting the pool surface from about 6 feet in the air has given enough bubbles and aeration to cause the pH to noticeably rise -- about 0.1 for every 8 hours of aeration starting from around 7.1

Though I could have just added some base, I thought I'd just try outgassing the same CO2 that I had added with the dry ice.

I hope everyone had a Happy Halloween.

Richard