Dropping PH

pnchowdary · Dec 17, 2021

I have noticed that my PH has started to continuously drop since last evening. It’s usually above 8.1. Last night I added some pods and phyto to the refugium. Usually my PH rises when my refugium light is on. However, it started falling last night and it has been going downhill, even after the DT lights turned on. I have checked my Alkalinity and it is at 8.1 and hasn’t changed for the last three days. I have attached the graph of my PH from apex. Could anyone please throw some light on what is going on and what I need to do to stop the dropping PH. My equipment details are in my signature. I would really appreciate any responses.

DH78 · Dec 17, 2021

My first step would be to verify the calibration of probe. Just put the probe in the calibration solution and see if it is off a significant amount.

pnchowdary · Dec 17, 2021

DH78 said:
My first step would be to verify the calibration of probe. Just put the probe in the calibration solution and see if it is off a significant amount.

Unfortunately I don’t have the calibration solution to recalibrate the probe. Maybe I will order some.

DH78 · Dec 20, 2021

If you have a ph test kit you can at least check it against the probe reading. Other than the probe being faulty/out of calibration, I'm not sure what else could cause that type of steady drop unless you are somehow adding an acid to the tank.

homer1475 · Dec 20, 2021

I would double check that probe before I did anything.

More then likely unless your adding some sort of mineral acid, the probe is failing.

pnchowdary · Dec 20, 2021

Thanks for all your replies. I believe I might have found the issue and fixed it. I had moved the magnetic mount of my Tunze refuge light closer to the ph probe. I am guessing that might have caused the interference with the ph probe. I moved it as far as possible from the probe and now the readings seem to be back to normal.