Anyone trust your pH probe?

Putting my Reef Angel info in my sig was a big motivator to calibrate my pH probe.

I had this probe in there for over a year. I calibrated it with the 7.0 and 10.0 solution. It still wouldn't raise above pH 4 so I tossed it as I had a new one.

The new one out of the box seemed pretty accurate (8.3 or so) but I decided to calibrate it. Now it shows my pH in the high 7's. This may well be fairly accurate. In my experience, my nano always has slightly low pH around 8.0.

Is there a trick to calibration? I let the numbers settle for over 5 minutes before hitting 'ok' on my Reef Angel.

But the point is, can I trust these things at all? Are they just a measuring stick?

Kinda frustrated with this.

matt

 

do you always use a 10 to cal I use a 7 and 4 to cal.

 

Hmm. Well I went with 10.0 per RA manual. Does yours recommend 4?

 

I used mine a gauge only. I used a pH test kit and then added a fudge factor to the controller's base numbers from calibration to move the reading out of I am freaked out territory.

 

I trust mine wholeheartedly. (mainly because I have two of them on a single tank) but once calibrated, a probe should be pretty accurate with the controller it is placed with. I have read you should re-calibrate every 6 months, but mine have seemed to stay pretty steady.

BTW and im sure you know this, but you are actually calibrating the meter (or controller) to read the signals produced by the probe itself when immersed in a solution. since every probe may read slightly different, this is why you calibrate.