Reasons for sudden spike in Ca?

[gmdcdvm]

Hello,
I am trying to trouble shoot a sudden spike in my Ca. I use a neptune trident along with red sea test kit to compare. While I was out of town I got an alert from the trident my Ca had reached 530, had been hovering around 430.
1. I had just changed the B and C reagents before I left town.
2. I use a red sea reefdose. I came home and doubled checked it. It is dosing volume accurately, but I recalibrated it anyway.
3. I confirmed with the red sea test kit the calcium level was around 520.
4.I checked the lines to look for any clogs.
5. I have not had a sudden loss of corals.
6. I have not added any new corals.
7. I have been slowly adding magnesium. My level was at 1200, Slowly raising it up and currently at 1290.
8. Alk-8.2.
9. pH between 8.1-8.3.
10. The spike happened over 2 days.
11. I get my saltwater from Cali Kids, did a large water change (60g) for a 180 tank before I left town, but the level was 430 after the change before I left town. I have not test the water from Cali kids, but figured that should be OK since the water change occurred 4 days before I left town.

I recently lost a few goni's and one hammer before this happened. The rest of the corals look good. Just wondering what happened so I can make the right adjustments as needed.

Thoughts?

Gerry

 

[Kensington Reefer]

Calibrate the Ca probe

 

[Alexander1312]

That would be a lot of excess dosing or under consumption.

A low PH could have released previously precipitated CA, but it does not look as if you had a low PH issue.

Since CA is very high, I would double-check with Salifert CA the accuracy before making any grand changes. I know Salifert is very accurate by comparing my results regularly with ICP. You can also come by, and we can check here.

Did you see a significant decline in alkalinity? Or greater need to dose alkalinity? This would potentially indicate an increase in CA.

 

[JVU]

Proper Mg levels stabilize Ca and Alk (prevent abiotic precipitation). So if you were having low-Mg related losses in Ca, and now you aren’t after improving your Mg level, then your Ca dosing may be more than you need.