Confused on Alkalinity Results

[Ryan_Lap]

So on the 7th of December I tested the alkalinity at it came back at 11dkh. I thought that was a little high, but attributed it to possibly not stirring the salt.

On the 16th of December I tested and it came back at 14dkh. Now thats weird that it would have went up without a water change or any additives added.

Changed 12 gallons of water on the 19th of December.

Tested again on the 23rd of December and the alkalinity came back at 14dkh once again.

Now Im confused, 14 is suppose to be on the extremely high side from what Ive read. Not sure as to why it would be so high, why it went up, and why it wont drop. All my corals look fine and the pH, calcium, and magnesium are all coming back at good levels. Ill add Im using IO salt.

Any ideas?