Can’t stop calcium increasing

[mfollen]

Hey reefers,

My calcium has slowly raised from 430 to 530 and now 570.

I am only dosing alkalinity and magnesium.

Previously my magnesium was low (1260) so not sure if the extra precipitation while dosing kalkwasser drove the CA from 430 to 530...
Once I hit 530, I took the kalkwasser offline and have only been dosing alk (Sea chem reef fusion2) and mag. During this time I expected the CA to decrease, but it has only risen.

Any idea why CA is still raising?

I have to dose Alk daily as I do have a number of small SPS frags growing, so CA should be getting consumed.

I’m worried that the CA gets any higher. Thank you!!

 

[mfollen]

Oh and alk is 7.6 and mag is 1320 currently.

 

[Randy Holmes-Farley Verified Community Expert]

What magnesium product are you using?

Tap water can have substantial calcium in it.

Some salt mixes also have very high calcium.

 

[mfollen]

Thank you @Randy Holmes-Farley

I’ve been researching and couldn’t find any related information..

Magnesium is BRS pharma mix: https://www.bulkreefsupply.com/magnesium-mix-for-general-adjustments-bulk-reef-supply.html
I believe it’s made of “7 1/4 c. Magnesium Chloride : 1/2 c. Magnesium Sulfate”

Using brightwell marine salt. Will check the calcium level of a newly mixed batch but a recent water change brought it down. So not sure if it’s the city tap water.

Thank you.

 

[mfollen]

Hi @Randy Holmes-Farley

Since conducting a water changer that got calcium down to 530, I’m now at 540 a week later..

The new saltwater used in the water change decreased calcium levels, so my source water is not the issue.

Could it be Seachem fusion 2 raising alkalinity? Fusion 1 is not being dosed.

The only other change during this time has been an increase in magnesium from 1320 to 1370-1380. Dosing the BRS pharma magnesium mix has been halted once the high value was noticed.

Any ideas as to what is causing the increase in calcium? I can not get it to go down with a 180 gallon mixed reef and a good amount of SPS frags which are showing slow and steady growth.

Thank you so much.