Is calcium inversely proportional to alkalinity?

[Dom]

Yesterday, my ALK was 11.2 with my calcium at 360.

Today, my ALK dropped to 9.8 with my calcium up to 400.

Seems like it is; just confirming.

 

[Alexraptor]

What is your magnesium at?

Proper magnesium levels are essential in order to maintain proper Alk-Ca balance, too low and carbon and calcium will readily precipitate into CaCO3 (Calcium Carbonate).

 

[BigMonkeyBrain]

Yesterday, my ALK was 11.2 with my calcium at 360.

Today, my ALK dropped to 9.8 with my calcium up to 400.

Seems like it is; just confirming.

I have not seen a relationship or equation that would predict the other from the one known value. I believe that they are independent variables.

Did you dose between the two tests ? Hard to even know if any precipitation happened without a trend line. I think I remember all Alk / buffer would be lost if a 50-ppm Calcium precipitation happened.

Randy : "Even if all the alkalinity in normal seawater was removed by precipitating calcium carbonate, the calcium would drop by only about 50 ppm."

PH should be included in these readings.


Probably happens !

 

[Dom]

What is your magnesium at?

Proper magnesium levels are essential in order to maintain proper Alk-Ca balance, too low and carbon and calcium will readily precipitate into CaCO3 (Calcium Carbonate).

Mag is 1600+

I'm not dosing Mag, just baked baking soda for ALK (9grams daily) and
Red Sea Foundation A for calcium (15ml daily).

 

[Dom]

I have not seen a relationship or equation that would predict the other from the one known value. I believe that they are independent variables.

Did you dose between the two tests ? Hard to even know if any precipitation happened without a trend line. I think I remember all Alk / buffer would be lost if a 50-ppm Calcium precipitation happened.

Randy : "Even if all the alkalinity in normal seawater was removed by precipitating calcium carbonate, the calcium would drop by only about 50 ppm."

PH should be included in these readings.


Probably happens !

I bake my baking soda additive to give my pH a bit of a boost. My pH sits consistently between 8 - 8.2

 

[BigMonkeyBrain]

Nice tank ! You have experience and know your tank. What is your guess ?

I will wait for the chemist ! I might learn something.

Probably happens !

 

[Randy Holmes-Farley Verified Community Expert]

Yesterday, my ALK was 11.2 with my calcium at 360.

Today, my ALK dropped to 9.8 with my calcium up to 400.

Seems like it is; just confirming.

No, that is not correct. There's no possibility that your decline in alk caused a rise in calcium.

Unless you dosed that large amount of calcium (40 ppm) overnight, it is just test error.