[Randy Holmes-Farley]

Limewater has a huge pH effect on the water, and if you are dosing more now because evaporation is higher, or a more concentrated solution is being made, then yes, pH will rise.

How high is it?

Aeration or less limewater are the best options.

Anything else you'll have to do every day, like adding some CO2 or vinegar or vodka, etc..