Calcium Consumption

[SWherrey]

@Randy Holmes-Farley

I hope you can help me on this one. I switched from All for reef to the BRS Two part and have been trying to lower my calcium as it is around 470. What has me baffled is I’m dosing 77ml of Soda Ash which is maintaining my Alk at 8-8.2 and I am also dosing 2600ml daily of kalkwasser. I know it adds calcium as well. Now I was dosing 62ml of calcium chloride and calcium was stable. Trying to lower calcium I completely stopped dosing the calcium chloride and in a whole day it dropped about 6ppm.

IDK what’s going on I find it weird. And there is no signs of precipitation or anything on my pumps. Is this possible?

 

[SWherrey]

It is an SPS heavy tank 75 gallon total water volume (estimated)

 

[Randy Holmes-Farley Verified Community Expert]

Kalkwasser is actually overbalanced to excess calcium relative to alkalinity. That is because it adds exactly the ratio of calcium to alk in pure calcium carbonate, but in real deposition of calcium carboante in a reef tank, magneisum (and a little strontium) gets into the calcium carbonate in place of some of the calcium. That is true whether it is deposited by an organism or by abiotic precipitation, but for organism deposition, the ratio of magnesium to calcium in the skeleton can vary.

The current calcium is fine, IMO, but if you want to lower it, keep not dosing the calcium part longer.

 

[Seansea]

Why do you want to lower it from 470?

 

[SWherrey]

Why do you want to lower it from 470?

Reef Moonshiner recommendation I’m aiming for 420-450

 

[Randy Holmes-Farley Verified Community Expert]

Reef Moonshiner recommendation I’m aiming for 420-450

While there's nothing wrong with that target, there is also no evidence it is better than anything else in the 400-550 ppm range.

 

[SWherrey]

While there's nothing wrong with that target, there is also no evidence it is better than anything else in the 400-550 ppm range.

Now is there some correlation between rising calcium levels and dropping magnesium or vice versa? I’ve noticed when my trident tests, at times my calcium will show it go up a bit then magnesium going down and then when calcium goes down magnesium goes up. These are not huge swings, very minor but it has always made me wonder.