Maxima looking stressed

[Ti]

Last week it was nice and open basking in the light.
This week it's more closed, mantle not showing, it jsut slips it;s lips in and out.
My Ca levels have been dropping, went from a stable 550ppm to 450 then to 400 and holding.
The Ph has recently slipped as well.
I went from a stable 8.3 to 8.1 during the day and 7.9 at night..
During the course of the week I have dosed kalk to bring the Ca up and seachem 8.3 buffer at night to try to get the ph up.
What should I do?

 

[Peabody]

What is your alk? What 8.3 buffer may have seriously unbalanced your alk.

 

[Ti]

I don;t have a alk test kit, so I;m not sure.
Some of the other corals are not looking too hot right now either.

 

[Peabody]

There you go. ALK is just as important, if not more, than CA. Stable high alk is crucial for clams, as well as important for most stoney corals. Get a good alk test kit (salifert) ASAP! Overnight one if you have to!!!

 

[Ti]

I did a water change and the clam is opening back to normal now.
The pther corals are looking better too.
I also swapped out the carbon and phosban.
Things are looking better.
But I will get the test kit.