CO2 question

[Limbo]

Aeration should be able to "stablize" the CO2 if there is an excess or a deficiency. Or at least thats how I read it. Replace it in the day and remove it at night by the same method.

Extract from Low pH: Causes and Cures (Randy Holmes-Farley)

Aerating the water with "normal air," driving out the excess carbon dioxide, will move the aquarium parameters along the green line of Figure 3, raising pH to just over pH 8.3. This effect is also what would happen if the growth of macroalgae were used to absorb some of the excess carbon dioxide, although it is rare for that effect to be able to move it all the way along the green line to above pH 8.3.

Extract from High pH: Causes and Cures (Randy Holmes-Farley)

Aerating the water, driving in carbon dioxide, is shown graphically in Figure 5. As carbon dioxide is added, the data point representing the aquarium's pH and alkalinity begins to shift horizontally from the "CO2 Deficient" curve to the normal CO2 curve (green line in Figure 5). Aerating with normal air cannot overshoot, and perfect aeration will land the aquarium on the normal CO2 line. Aeration with interior air that may contain excessive carbon dioxide can overshoot the pH target, and drive the aquarium's pH even lower (Figure 6).