Question for Dr. Randy: What causes dinural PH shifts?

[johnjjk]

Dear Dr. Holmes-Farley,

What causes diurnal PH shifts?

Is it only the algae reversing the photosynthesis at night (without light) and becoming Oxygen consuming and expelling CO2?

Or are there other additional factors?

Thank You
John Krivda

[Randy Holmes-Farley]

Yes, it is the consumption of CO2 by photosynthesis during the day, and the genertion of CO2 24 h/day, but more at night that causes the pH to rise during the day and drop at night (unless you add additives at special times, which may also cause pH swings).