Alkalinity affecting pH

[kevin_e]

So for the last 4 days my pH ranged from about 8.15-8.30.

The last 24 hlurs, however, has seen the pH range from 7.93-8.05 right now.

I tested my alkalinity and found that it dropped from 180 ppm to 160 ppm over the last 7 days. Not that I am really concearned about the pH range, just curious if the loss of alk could have contributed to the lower range of pH? Loss of buffering capacity seems probable, just not sure if 20 ppm can have that much of an effect.

Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

Yes, lower alk inherently leads to lower pH. The effect of a 20 ppm drop in alk is small, however. Alk doubling means about a 0.3 pH unit rise.