I have a reservoir(actually just a small tub) to prepare the water for my apistogramma tanks. I utilise the PH monitor to monitor the PH. This monitor has a probe which I place in the reservoir permanently. It gives PH readings of around 5 usually.
Lately, I got a new PH pen and got it calibrated. Used it to test the PH in the reservoir. Surprisingly, it give a different reading, which is 6.3. This I see it as quite a big different from that of the PH monitor. Initial thought is that I will need to recalibrate the probe of the PH monitor. That's what I did. Upon doing that, I find there's no problem witht he PH monitor, it's as accurate as it should be. By-the-way, the PH monitor is pretty new too.
So what's the problem? Both PH pen and PH monitor are calibrated using the same solution, but they gives different reading, a different of about 1.3.
Which should I trust? sigh....
Lately, I got a new PH pen and got it calibrated. Used it to test the PH in the reservoir. Surprisingly, it give a different reading, which is 6.3. This I see it as quite a big different from that of the PH monitor. Initial thought is that I will need to recalibrate the probe of the PH monitor. That's what I did. Upon doing that, I find there's no problem witht he PH monitor, it's as accurate as it should be. By-the-way, the PH monitor is pretty new too.
So what's the problem? Both PH pen and PH monitor are calibrated using the same solution, but they gives different reading, a different of about 1.3.
Which should I trust? sigh....