Calcium Levels Not Going Up With Dosing

[MDProuty]

I have a 75 gal reef tank and my calcium levels have been between 214 - 281 since testing with my Hanna Calcium Test Kit. My target calcium levels are 420 ppm. I've been dosing with BRS calcium chloride at approximately 400 ml/day to increase my calcium by no more than 50 ppm/day; however, my calcium levels are not increasing. I only have three coral in my tank, so I can't imagine they are depleting my calcium that fast. The only other thing I can think of is I didn't mix my BRS calcium calcium solution correctly, although I'm 99% sure I did.

Some of my other levels:
- pH: 7.77 (also trying to bring up through my calcium dosing)
- Salinity: 1.025 d SG
- Alkalinity: 159.2 ppm (8.9 dKH) - this was brought up from 134.2 ppm (7.6 dKH) using BRS soda ash solution in one dose
- Magnesium: 1,400 ppm - this was brought up from 1,300 ppm using BRS magnesium solution in one does

Any thoughts of what might be going on?...

 

[Randy Holmes-Farley Verified Community Expert]

I suspect the kit is off. Calcium very rarely gets that low. Assuming you are dosing the correct amount of calcium chloride, there is no way it will not rise.

Try the Hanna on some new salt water.

 

[vetteguy53081]

May be false reading otherwise not enough being dosed or being consumed at a high level

 

[MDProuty]

I suspect the kit is off. Calcium very rarely gets that low. Assuming you are dosing the correct amount of calcium chloride, there is no way it will not rise.

Try the Hanna on some new salt water.

That's a great idea! I'll try testing on some new salt water to verify the kit is reading correctly. Thanks...

 

[MDProuty]

If my Hanna tester is faulty and I've been dosing more calcium than I should, is there a way to bring the calcium back down or should I just let it drop with water changes?

 

[nereefpat]

I haven't used the Hanna Ca checker, but I've seen lots of people have trouble with it. I would get a cheap API Ca kit, and see what you get, and compare.

If my Hanna tester is faulty and I've been dosing more calcium than I should, is there a way to bring the calcium back down or should I just let it drop with water changes?

Ca would have to be really high to be problematic. Really, the only safe way to lower Ca would be water changes or let it come down slowly on its own....similar situation to those trying to lower alk in a display.