Reducing calcium while keeping Alk the same

tenurepro · May 2, 2020

Hello -
I have a redsear reefer 250 (250 L total volume). I dose ESV b-ionic 2 part to maintain parameters - typically about 8 dkh and 450 ppm calcium. ESV recommends dosing equal parts of the alk and calcium supplement, which i 've been following closely, but this - very gradually over about a year - raised my Calcium to 550 ppm (real reading with Trident, double checked with a fresh calcium salifer kit)... Let me say that this has not have any adverse effects on my SPS... But still, i am trying to get my calcium back to 450 by dosing less (50% less) of the ESV calcium supplement. However, this is leading to my alkalinity increasing to about 8.7 over 2 days....

so, not sure how to go about balancing alk and Ca.... I did of course consult @Randy Holmes-Farley awesome article

Chemistry And The Aquarium: Solving Calcium And Alkalinity Problems

I hope this article proves useful is understanding and dealing with the different types of calcium and alkalinity problems encountered by reef keepers. Once you get calcium and alkalinity under control, you are far along the road to having your tank chemistry optimal for its inhabitants.

reefs.com

The suggestion there is to increase alk (above 11 dkh) until Alk and CA are balanced and then dial everything down, but i would like to avoid raising alk that high... is there a way to rebalance Ca without increasing Alk ?

GoVols · May 2, 2020

Stop dosing your calcium and let it fall back into place. Then only dose the correct amount to hold it there.

At the same time you've stopped dosing cal, to let it fall back in place:
Only dose the correct amount of alk to hold it in place, as well.

There is only one product that I ever used that broke down to even daily doses of all the parts over the long haul.