I have a two tanks, each with a Neptune Controller. When adding the controller to the second tank its PH read about .3 lower than I expected. I used a cheap YINMIK pH meter I "confirmed" the new neptune was off by .3 compared to my other meters.
After calibrating it repeatedly and buying a new probe it's still "off" by .3. Next, I calibrated the YINMIK pH meter and now it agrees with the "inaccurate" one. A cheap API test kit has my entire family agreeing that none of the colors really match up correctly.
At this point I'm a bit spun around and I don't know what to think. A little research says some of these tools claim to be accurate by +/- .4. What?!?! I can put a piece of tape on the glass that reads 8.2 and be accurate by +/- .4.
Question: I want a PH meter I can trust. What should I buy?
After calibrating it repeatedly and buying a new probe it's still "off" by .3. Next, I calibrated the YINMIK pH meter and now it agrees with the "inaccurate" one. A cheap API test kit has my entire family agreeing that none of the colors really match up correctly.
At this point I'm a bit spun around and I don't know what to think. A little research says some of these tools claim to be accurate by +/- .4. What?!?! I can put a piece of tape on the glass that reads 8.2 and be accurate by +/- .4.
Question: I want a PH meter I can trust. What should I buy?