Is sustained high Calcium (520 - 540 ppm) a concern?

[jessezm]

Hi all - I've been measuring above 500ppm calcium in my tank (new Salifert test kit) for about the past 2-3 months (before that it was in the high 400's). I'm just wondering if this is something I should be concerned with or not.

Alk is between 7 - 8 (targeting around 7.5) (Red Sea Pro)
Mag is 1350ppm (Salifert)
pH between 8 and 8.2 generally (Apex) - average the last 2 weeks is 8.11
PO4 is .02 ppm (hanna ULR)
N03 undetectable with Salifert kit

I am currently running a Korallin 1502 calcium reactor (controlled with Apex and using Carbon Doser regulator) and adding Kalk to my ATO to help keep the pH up. Total system volume is about 85 - 90 gal. The tank itself is 45g and it is wall to wall SPS frags and small colonies.

I'm adding Red Sea Reef Energy A and B to help counter low nutrients. I am getting growth, although it does seem like it has slowed over the past couple months. But I'm wondering why my calcium would remain so high even as the Alk just keeps up around 7 to 8 dKh (and Mag is stable). And should I be concerned? I have seen Randy write that calcium that high isn't a concern, but I guess I just want a bit more reassurance that something isn't way off that I'm not thinking about. Thanks!

 

[jessezm]

Okay well I just retested twice with a hanna calcium checker and got 572 ppm both times. Is this level a problem?

 

[Shredded]

I quit using my new Hanna Calcium checker shortly after I got it because the levels read well over 500 which did not match any of my other brands of tests. While at MACNA I talked to their rep and he told me that the problem (he told me before I could even finish my question) was I was using my RO/DI water in the first step along with the reagent. He told me that frequently the effluent from your RO/DI, depending upon your water source may contain calcium that passes thru the membrane. No one cares about this because extra calcium is never an issue to your tank. He told me to go to the pharmacy and get pharmaceutical grade distilled water and use that instead. (grocery store grade would probably be fine) Problem fixed. Reads right on the money every time.

 

[jessezm]

Ah very good to know! But even with Salifert my calcium has been reading 510 ppm to 525 ppm (Hanna checker was like 560 ppm!). I'm going to be adding 150 gallons to the system soon so hopefully things will stabilize a bit lower. But still interested to hear if this is an actual issue to worry about, as it seems rare that people have levels this high...