I have been experiencing a chronic increment in pH & EC values after a while in my system. You can easily observe them through the charts below.
This represents the pH and the EC rates alone. You can see that it starts skyrocketing for no reason.
This represents the pH & EC function behavior w.r.t the pH values. I use 63% and 5% concentrated pH down (NO3) & up (KOH) solutions, respectively.
This represents the moments that A & B solutions were pumped into the water tank.
I have tried many things like changing the pH up & down brands and A & B nutritions and recalibrating the probes to solve the issue, but none of them worked. Lately, I have noticed that when EC gets involved in measuring the rates along with the pH probe, it starts affecting the pH measurement after a point and the values become unreliable concerning the actual rates. The weirdest thing is that no matter how much acid gets pumped into the water tank, it continues to climb. However, I measure between 0-1 (minus values to the end) as soon as I pull the EC probe off from the tank. Due to financial reasons and stock problems, I had to use DFRobot’s Gravity: Analog pH meter V2 and Seeed EC sensor including a single 16-bit ADC. Once, I came across the need for electrical isolation between the sensors over the Internet. I do not use any professional isolator or anything designed by me (no experience with this). But, I tried to separate the pH and the EC circuits by moving the pH circuit to an external ADC. I concluded that it is not counted as isolating the circuits since it didn’t work
I would appreciate any suggestions and definitely want to hear about similar issues that are solved. Thanks in advance!