PH recently trending down - probe breaking in or something else?

[IPT]

Hm, so in the last few days I am seeing a trend toward a lowing of Ph curve across all hours. ALK has generally remained stable except for a slight increase after a WC. it's not radical, but it did get my attention and I am wondering if anyone has any thoughts.

I will add that I notes this one two different devices both using Milwaukee probes that were just calibrated a week or 2 ago. Maybe this is a normal drop off after installing a new probe and it will stabilize?

 

[edsbeaker]

A probe doesn’t need a break in time. It should work from the start after being calibrated.
Have you had additional people in the house, closed any windows, turned off your skimmer, dosing less Alk? Any environmental changes that may be affecting the pH drop?

The pH is in a good range, though, so I wouldn’t be concerned, but you are probably trying to figure out why.

 

[Randy Holmes-Farley]

Assuming it is accurate and not just calibration drift, the difference likely relates to changes in the home air CO2 level.

 

[IPT]

Yeah, the tank is in an office environment so things are pretty roomy with few people, and the conditions pretty consistent.

That's what's perplexing me. My dosing of Alk, Ca, and Kalk are all fixed and stable. Though I did have a bump in Nitrates after adding too much trying to bring it up. I was trying to chalk it up to something metabolic in the tank or mechanical. Probes are new and calibrated in the past two weeks. I doubt they would both drift simultaneously if at all that quickly. I don't know but maybe the sudden No3 change bothered the coral and slowed growth causing Ph to fall?

Yeah, it's not too low, I am just seeing a trend starting and am trying to understand what may be happening. I'm not worried, yet, just observing and trying to understand my tank as best I can.