Podam:
I do appreciate your friendly advice. Perhaps I was too "blunt".
I have seen several newly established tanks on these boards which reported 600-800ppm calcium. Usually with a calcium source like crushed coral or dead coral decorations. It seems to me that when a newbie uses those, fills a tank with fw, and adds the salt, then a high amount of calcium would be expected. Then after a little while the calcium would decrease to normal values just as part of the normal stabilization of the tank.
In this particular case Kalk was being added. Therefore, calcium is being added without the carbonate ion. With the resulting high calcium and low carbonate.
With a tank that has thriving livestock and is otherwise ok, the safest thing to do is to just stop adding the kalk and monitor what happens.
To me it just appears that the calcium load of the livestock is not consuming the calcium being added.
Sure you could check the test kit, and that may be the problem.
but I suspect the test kit is accurate.
and sure it could also be low mag.
But what should he do? Reach for another bottle to dose the system with? Start chasing parameters? Add a third supplement? Spend $100s on equipment to correct this "problem"?
Or simply cut back on the kalk and monitor what happens.
Perhaps you or others can tell me where in this particular case that logic is incorrect? And BTW stopping the kalk is doing something.