Wide range of alkalinity values between two testing methods

shawn95id · Jan 30, 2023

I am running a Trident with my Apex and get 4 ALK readings a day with that, all ranging right around 9.0 give or take. I check ALK with a Hanna checker a few times a week and usually get at least a full point higher (between 10.0 and 10.4). I have calibrated the trident several times lately and that doesn’t seem to fix the gap.

My corals aren’t thriving, in fact some of the SPS are suffering. I’m wondering if my ALK is too high and that might be causing my issue, because the rest of my chemistry seems to be in line with recommended values.

Other chemistry values are as follows:
Ph: 8.25 - 8.45
Salinity: 35
Calcium: 4.29
Mag: 1367
Temp: 77.7
Phosphates: .03
Nitrates: 11

Tank Info:
Age: 1 year
Size: 110 display, 38 sump

Would love some help troubleshooting why my corals aren’t thriving and some seem to be dying.

Thanks!

Randy Holmes-Farley · Jan 30, 2023

I don't think that alk difference would cause corals to not thrive.

Did you try the Hanna on the Trident calibration solution?

shawn95id · Jan 30, 2023

Randy Holmes-Farley said:
I don't think that alk difference would cause corals to not thrive.

Did you try the Hanna on the Trident calibration solution?

No, that’s a great idea, I’ll give that a try. Are you seeing anything else in my numbers that might be causing an issue? If not then is it down to lighting and flow? (Probably not that simple huh?)

shawn95id · Feb 3, 2023

Randy, I ran the Trident calibration solution through the Hanna checker and Hanna read it about a full point higher than the label on the solution. So looks like there's an issue with the Hanna checker. Thank you for the suggestion.

Randy Holmes-Farley · Feb 3, 2023

shawn95id said:
Randy, I ran the Trident calibration solution through the Hanna checker and Hanna read it about a full point higher than the label on the solution. So looks like there's an issue with the Hanna checker. Thank you for the suggestion.

Or an issue with the standard. I’m not sure exactly what it is or how it is made.