Using ANY method of raising pH (except fresh air to the room) is typically fighting against aeration at the tank top with high CO2 air. High aeration and high CO2 often wins out.
I have a CO2 meter which always reads atmospheric levels, mainly because I usually have outside ventilation coming in. Despite this, I have large swings,. However, when I was using a massively oversized skimmer (rated for systems 10x the size it was connected to), with the skimmer drawing in nearly 1,000 of liters of air per hour AND attached to a CO2 scrubber on top of drawing in air from outside, I still saw a swing of .2. So is it even possible to aerate enough to prevent a swing? I’m not that worried about it, seeing as the ocean has one also and it’s not preventing growth in my systems, but I’m just curious as to what crazy level of aeration would have to be utilized to prevent a swing due to CO2. For the time being, I don’t worry about it, one of my tanks fluctuates between 7.8 and 8.4 each day, the other ~8.0-8.35. I also don’t use skimmers anymore, but I do aerate with air pumps.
Btw, pH probes need calibrated a lot. I like to run 2-3 per system also just in case.