Kalk raising Ph but not Alkalinity

[Bustyraker]

I added a Kalk Stirrer 2 days ago to my system and over the past 2 days my Ph has risen from an average of 7.8 to 8.0. I started out with a DKh of 9.2 and now have a Dkh of 8.4. My zoas do not seem happy most of them are closed and my elegance coral is very deflated. All of my other corals LPS and SPS seems fine and happy. Wondering if the rising PH has something to do with it and wierd that its not also raising alkalinity. My Calcium is at 450ppm and Magnesium 1400.

 

[Miami Reef]

It’s impossible for calcium hydroxide to not raise alkalinity. If the test kit is accurate, the only solution is to increase the dose.

 

[Gone Reefin’]

Possible that increased pH has spurred on growth, thus increasing alk demand?

 

[Jamie814]

It’s impossible for calcium hydroxide to not raise alkalinity.

While this is true, kalk can also cause precipitation due to the high pH when it hits saltwater, thus lowering alk. This issue can be reduced by dosing it in a high flow area.

 

[Bustyraker]

I think if my alk continues to drop tomorrow morning I will increase my dose. I also just tested No3 and Po4 and No3 is undetectable and Po4 is .09. I ordered some Brightwell Neo Nitro to help balance things out. Ive been having issues keeping nitrates up in this tank and I feed twice daily.