Calcium levels

[Jridgel47]

Hello everyone I have a question to ask last week my cal level was 420 this week its at 380 does that mean the corals I have in ny tank are growing...also how do I raise it back up ....everything else is fine salinity is .024 and alk is at 10....TIA

 

[SPR1968]

Probably yes, you need to get a calcium supplement and start adding it accordingly to uptake, and the instructions on whatever you use, same with alkalinity and magnesium when they start to be depleted

Ideally add them daily to try and maintain stable parameters

Also if your unsure or in doubt of the result, re test to make sure it’s not a test error, before you add to much of anything

 

[Randy Holmes-Farley Verified Community Expert]

Hello everyone I have a question to ask last week my cal level was 420 this week its at 380 does that mean the corals I have in ny tank are growing...also how do I raise it back up ....everything else is fine salinity is .024 and alk is at 10....TIA

If the alk has not changed, it may just be test error for the calcium.

 

[Jridgel47]

If the alk has not changed, it may just be test error for the calcium.

No the alk hasn't changed ill try to retest thanks ....if cal drops does alk generally drop as well or go up

 

[Randy Holmes-Farley Verified Community Expert]

No the alk hasn't changed ill try to retest thanks ....if cal drops does alk generally drop as well or go up

Calcium cannot ever decline without alkalinity being consumed (or a salinity change). About 2.8 dKH of alk is consumed for each 18-20 ppm calcium.

So unless alkalinity was added back for some reason, the calcium test is just showing random variation, which is pretty normal. It's not really worth trying to see changes in calcium on that scale. it is just noise.

That said, it is fine to boost it to be conservative, because calcium is fine from 400 to 550 ppm.