Review on 🌊 Ultimate Water Quality Tester: 2-in-1 pH & Temperature Meter, BNC pH Electrode, Ideal for Aquariums, Hydroponics, Tanks, Aquaculture & Laboratories by Mark Morrow

The thing is scrap. It is not calibrated at all. I tried calibrating with 3 different calibration solutions 10, 7 and 4 and the result was not even remotely accurate. I calibrated it first with a 10 calibration solution after thoroughly rinsing and drying the probe. I then calibrated with a 7.0 dilution after rinsing and drying, and it was off by 0.27 when placed in a 7.0 calibration dilution. So I calibrate it to a 7.0 dilution, clean and dry it thoroughly, and go back to a 10 dilution. Deviation by 0.17. I will recalibrate with dilution 10 and then check calibration 4. Disabled at 0.19. The thing doesn't calibrate properly at all. Do not trust this monitor at all, it is not accurate. I'm lucky I didn't kill everything in my reef tank by trusting this piece of crap.