Calcium Very High


New Member
View Badges
May 29, 2023
Reaction score
Rating - 0%
0   0   0
hello, I started with a post about my torch, coral dying. All of our parameters were great I thought. My new Hanna calcium checker was in the mail. And I just really wanted to have all the checkers. I didn’t think anything was wrong with the calcium at all. But I never checked it. We brought everything over to our LFS who helped look at everything and uncover that the calcium was way high. I’m not entirely sure how that could happen and I was curious if anyone knew?
The one thing that changed was - about a month ago we had a low alkalinity issue and ended up dosing alkalinity and then doing a gradual water change with instant ocean Crystal and RO water.
Prior to that we were using boxed ocean water.
After about a week or so, from that change to instant ocean/ RO - everything started to crash. Every coral we had was going downhill.
Any idea?


1635 magnesium
8.1 nitrate
7.8 ph
9.4 alkalinity
1.024 salinity


7500 Club Member
View Badges
Jul 22, 2018
Reaction score
Province of Ontario
Rating - 0%
0   0   0
Not sure what “everything” means in your system. More than the torch?

Stability is king and the change from one to another may have messed up your chemistry, torches hate this most as well as any move once happy.

I had no luck with Hanna CA checker. Varied widely in the results. Salifert colour change pink to blue is easy to see.

Not sure what your vision of high calcium is? I’m running 480ppm at the moment with no issues.

Your numbers look good but I’d push 1.024 to 1.025-6.

I don’t see a phosphorus or phosphate number and that one is important, should be 0.05-.1ppm and stable, or everything starved out. Only the Hanna I know works with this measure as the colour change is so, so, small, it’s hard to pinpoint a number.

From time to time, any parameter can go south so testing is important especially, temp, SG, N and P.

Purple rock rocks! Do you have coralline algae in your tank right now?

  • My tank is overrun with coralline algae.

    Votes: 15 9.0%
  • I have a manageable amount of coralline algae right now.

    Votes: 65 39.2%
  • I have just a bit of coralline algae right now.

    Votes: 56 33.7%
  • I have had coralline in the past, but not currently.

    Votes: 17 10.2%
  • I have never had coralline algae in my tank.

    Votes: 10 6.0%
  • Other.

    Votes: 3 1.8%