Calcium reactor - high calcium and low alkalinity

[kingmaximus]

From two months i have been using calcium reactor on sps dominated 75 gallon tank. The calcium is stable around 430 ppm but the alkalinity keeps dropping if i dont dose alkalinity. Its like my tank is using alkalinity more than calcium.

how can i keep both Ca and Kh stable using just calcium reactor?

 

[Randy Holmes-Farley Verified Community Expert]

From two months i have been using calcium reactor on sps dominated 75 gallon tank. The calcium is stable around 430 ppm but the alkalinity keeps dropping if i dont dose alkalinity. Its like my tank is using alkalinity more than calcium.

how can i keep both Ca and Kh stable using just calcium reactor?

It likely is not using an imbalanced amount in that sense, unless nitrate is rising rapidly. Alkalinity responds much faster (on a percentage basis) to over or under dosing than does calcium, because seawater has far more calcium than alkalinity.

Set the reactor to meet the alk demand and see what happens to calcium.

 

[kingmaximus]

It likely is not using an imbalanced amount in that sense, unless nitrate is rising rapidly. Alkalinity responds much faster (on a percentage basis) to over or under dosing than does calcium, because seawater has far more calcium than alkalinity.

Set the reactor to meet the alk demand and see what happens to calcium.

I was out for a month and alkalinity dropped to 4.5 so slowly increasing it back. Let me try setting it for Alkalinity. Thanks for the help.