The best way is to bring balance with water changes and then use equal parts of "A" & "B" to maintain your calc/alc.
However more times then not, the test is simply wrong. It could be more then a year old or inaccurate. Before you start doing drastic changes and adding more of anything recheck with different test or again water change is oldest and safest way to balance the system.
This can be hard to achieve if you system has large water volume, in that case you can just buy more accurate and fresh test kits.
Also when Alk is high calc will always drop, everyone’s crying story…and this will bring you back to water change
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Calcium reactor is more stable way to go, but then be prepared that Ph will start to drop because of acidic (Low Ph) effluent from the reactor and second calcium media chamber or kalkwasser additions may be needed.