Can I just dose calcium?

blkhawk10 · Feb 17, 2016

I've been having an issue keeping my calcium above 400 for an extended period of time now...My alkalinity is at 8.3 dkh which I would like to be in the 7's but for now that's ok...Can I just dose calcium daily to maintain a level above 400 and in doing so will the alkalinity drop down to where I want it to be?

Randy Holmes-Farley · Feb 17, 2016

The only way calcium declines when alk does not is if a salt mix used for water changes has low calcium.

But yes, it is fine to dose only calcium if, that is all that is needed.

What salt mix are you using and at what salinity?

blkhawk10 · Feb 17, 2016

Instant ocean at 1.025...I bumped up my calcium the 3rd of this month to 430 and it's now at 390...my alkalinity started out at 9.3 dkh and how now gone down to 8.3 dkh.

Randy Holmes-Farley · Feb 17, 2016

Yes, IO at that salinity will have pretty low calcium, and that would be the reason.

One option is to raise the sg a bit, and another is to boost the IO before it gets to your tank.