Calc low and alk ok

[wasabi bean]

So my calc has always been very steady and my alk was low, i have now been dosing alk for a while and it is now at 10.2, this now means my corals are starting to actually grow and is draining the calc. It is now quite low 380 and my pavona looks pretty rough, the calc powder arrives in 2 days, should i then dose some kalkwasser today to risk high alk and get the calc up or should i wait it out for the two days. Also i dose sodium bicarb for alk every hour so is it fine to add the calc to the top off even if sometimes it could be added at the same time?

 

[Randy Holmes-Farley Verified Community Expert]

What is the salinity? Low salinity is a common cause of low calcium and magnesium at OK alk.

 

[wasabi bean]

My salinity is pretty constant at 1.026-25, i never used kalkwasser so i only increased calc when doing WC while actively dosing only alk using sodium bicarb

 

[Randy Holmes-Farley Verified Community Expert]

My salinity is pretty constant at 1.026-25, i never used kalkwasser so i only increased calc when doing WC while actively dosing only alk using sodium bicarb

You add alk and not calcium, of course calcium will decline. Yes, you can add calcium to the top off. Never try to raise calcium with kalk. Alk will skyrocket.