What type of tank do you have and are you currently dosing anything?
In short, alkalinity is a measure of the total carbonates in the water and is an indication of the waters ability to resist changes in ph
. It is not an actual measure of ph
, they are two different things. If you are maintaining alk
, both should be monitored to maintain a proper balance. When one is altered it affects the other.
I would suggest reading the following, they may help you clear things up...
Calcium and Alkalinity
by Randy Holmes-Farley