Maximum Allowable PH Swing in 24 Hours

[PatMayo]

Hi Randy and everyone else.

What is the maximum allowable PH swing for any 24 hour period.
As I understand it there is typically an upswing during the light period and then it lowers at night when the lights are off. What kind of swing should I be working to maintain?

Regards,

Pat

 

[Randy Holmes-Farley]

IMO, the actual swing is not important, but rather the extent of the extremes. So IMO, pH 8.2 to 8.5 is fine, but 8.5 to 8.6 is less desirable. Same for pH 7.8 to 7.9 being worse than pH 8.0 to 8.4. The reason for thinking that is that I do not believe that most organisms "adapt" in any important way to diurnal pH changes.