Low PH, High Alkalinity

[Tombones]

I have a total of 100 gallons reef aquarium and live in Florida where recently it has been cool and I have been keeping the windows open to raise the ph. The ph has always been low and never above 8.0 dkh. I started dosing 2000 ml Kaltwasser each 24 hours to raise the ph but nothing changes expect my alkalinity. Alk has gone from 7.3 to 9.3 in 5 days. I mixed the Kalk at 2 teaspoons/gallon and the solution ph is 12.3
I also just bought a new ph probe and calibrated it. What am I missing. Why wont the ph raise? I am leaving for Chicago tomorrow, so I am turning off the kalk doser for fear of alk getting too high.
Any ideas?

 

[ナイトコア猫]

CO2 from the house and the biological load (including things like fish, bacteria) is lowering pH. My comments here might help:

https://www.reef2reef.com/threads/new-tank-ph-and-kh.957071/post-10912530
It seems I can't easily copy that kind of post over here.

 

[taricha]

Do Randy's trick. Bubble a cup of tank water with outside air for like an hour.
You should measure pH at the expected value for your Alk. This would confirm that CO2 in the water is your issue.
If your pH stays around the same low value when bubbling for an hour with outside air, then it says CO2 isn't your problem, but your pH meter is miscalibrated or otherwise malfunctioning.