My system was operating smoothly for the past couple of months (using DFRobot EC and pH boards with parasitic insulator, Apera instruments EC and pH probe, and Atlas PT-1000 temp probe… all in I2C).
A few nights ago it started going crazy and after rebooting the I2C went offline. Had to disable and re-enable it to start it back up, but it started having some off behavior. See the asynch graph below. Anyone has any idea what this could be? Or any recommendation on what to try? System is outdoors, but it is inside an enclosure protected from the elements.
Pi? Power issue? One failed sensor fouling the others? I’m only running Atlas pH and PT-1000 off my Pi3 with T3 board. I know I’m due to down the system and bring everything indoors to calibrate since my PT-1000 has been inaccurate for months.
I am running a RPi4b. I do not think there was power issues as of late. I am using the rpi power supply, and it is all mounted on a surge protector too. The temp sensor seems to be behaving well, I think the pH/ec sensors are the ones that might be acting up. I had to recalibrate them and restart the pi multiple times until they were back online giving reasonable data…
After a few days, the behavior started again. I purchased an Atlas lab-grade pH probe to see if it is the probe. I will update a few days after it arrives and gets installed
Get rid of the Atlas pH sensor and just test your pH by hand every day or 2 using pH strips or pH drops. If you’re using proper buffered pH up and pH down solutions then your pH should not fluctuate too much over a day or 2 period. If it is, then there is something else going on that you need to fix. There are very few pH sensors that are designed to be used continuously, and the ones that are, are very expensive and simply not worth it when there are simpler, cheaper, more traditional options than a sensor.
There is also no real reason to measure EC. If you are mixing your nutrients according to the manufacturer’s recommended ratios, then you should not have to worry about EC. There is absolutely nothing you can do to change the EC reading except add fresh water to dilute the nutrient solution anyway, so it’s really not a useful or meaningful measurement of anything other than the electrical conductivity of the nutrient solution which approximates the Total Dissolved Solids in that solution… anything you add to the solution other then fresh water will only raise the EC reading… and temp fluctuations will also cause wide swings in the EC readings… this is why having your system outdoors is not recommended, temperature fluctuations will cause changes in your pH and EC readings. If you have no control over the temperature in the grow space or the reservoir, then you really aren’t doing “hydroponics”, you’re just doing “drip irrigation”. Temperature control is one of the most important factors in controlling many other aspects of a hydroponics system such as relative humidity, VPD, pH, EC, etc.
