Alkatronic keeping Calcium levels stable

[Erich01]

I bought an alkatronic a month ago and it keeps my dKH between 8.5-9.0. I double-checked it against my Hanna alkalinity meter. I dont have a doser for calcium so I just check with Hanna and see that it continually reads 435-460. Ive heard some people say that constantly dosing alk keeps Ca in check but this seems very wrong to me. Why are my Ca levels high and pretty much stable just by dosing a solution of sodium bicarbonate? Maybe I need to get a new Hanna Calcium checker? Any thoughts?

 

[Erich01]

I bought an alkatronic a month ago and it keeps my dKH between 8.5-9.0. I double-checked it against my Hanna alkalinity meter. I dont have a doser for calcium so I just check with Hanna and see that it continually reads 435-460. Ive heard some people say that constantly dosing alk keeps Ca in check but this seems very wrong to me. Why are my Ca levels high and pretty much stable just by dosing a solution of sodium bicarbonate? Maybe I need to get a new Hanna Calcium checker? Any thoughts?

My tank is heavily stocked with SPS and I have not needed to add calcium in over a month. I check calcium with my Hanna meter every 3 days and its never below 450.

 

[Dennis Cartier]

This is a common situation. It is harder to see the movement of calcium as compared to alkalinity as there is so much more of it wihtin the water column. So changes in alkalinity are obvious and changes in calcium levels often get lost in testing noise.

That being said, for every 2.8 dKH of alkalinity being used, calcium will be lowered by 20 ppm. So if you have been dosing alkalinity only, your calcium is going down, but your tests are not able to detect the changes.

 

[Randy Holmes-Farley Verified Community Expert]

I bought an alkatronic a month ago and it keeps my dKH between 8.5-9.0. I double-checked it against my Hanna alkalinity meter. I dont have a doser for calcium so I just check with Hanna and see that it continually reads 435-460. Ive heard some people say that constantly dosing alk keeps Ca in check but this seems very wrong to me. Why are my Ca levels high and pretty much stable just by dosing a solution of sodium bicarbonate? Maybe I need to get a new Hanna Calcium checker? Any thoughts?

Those levels are perfect. I recommend 400-550 ppm.

The calcium checker is only accurate to 450 +/- 27 ppm by Hanna's own claims of accuracy.