Review on Apera Instruments AI3211 Measurement Electrode by Dustin Citizen

Bought this model about 4 weeks ago. the first week went well. I did a three point calibration and it failed the 4.0 test. So I had to work with 7.0. I contacted Apera support and spoke to a technician. We did a factory reset and a few tests and they suggested visiting Revain. That's exactly what I did. Installed a new one, worked flawlessly for a week. I went to a weekly calibration and got an E5 error (probably a bad sensor or wrong decision in the manual). It reads fairly accurately at the time of the error but is still disappointed after spending so much money on a tool I need every day. I check about 25-50 plants daily and need this for my business but I need it to work reliably for more than a week. Maybe I'll look at Hanna or another brand. . Not sure what I'm going to do at this point, just pissed off and disappointed.