I’m still using my old Blue Lab pH meter. It was considered state of the art in its day.
I paid over $300 for it. It’s cumbersome, clunky , has a lot of wires that are always tangled. Needs to be constantly calibrated. But, it works.
Now I see a host of pen size meters, that all guarantee high accuracy. Best of all, there around $30.
Is it worth switching, or should I stick with old faithful?
I like my little Apera…rarely needs calibrated and works great
All pH meters require periodic recalibration if you want to be able to trust their measurements. My Bluelab Soil Pen displays a reminder every 30 days – it’s never seemed bothersome to me.
I worked at a metals testing lab for 12 years before my current job and I got used to calibrating a pH meter prior to taking pH readings once daily minimum. So as others pointed out the need to calibrate is always going to be there regardless of meter. Complementary to that is the need to keep relatively fresh pH calibration standards as they do degrade, especially if you’re not diligent in preventing contamination of the standards, e.g. failing to carefully rinse of a pH 4 standard before calibrating with a pH 7 standard. With fresh standards if your current pH meter needs minimal adjustment to bring it in line, no way would I buy a new one. The lab I used to work at certified pH pen meters for plating shops that were required to keep their plating baths within tight ranges to keep their military and Boeing certification. When platers would give us their brand new pen pH meters we’d measure their accuracy against our certified top of the line Fisher instruments bench top meter. What we’d find is out of a batch of 10, the majority of the time most of the tested meters would be great but it wasn’t that uncommon to test brand new meters that functioned perfectly but they read too far off to certify. These were top brand pens too not cheap imports. Long winded way to say buying a new pH meter could possibly put you in a worse situation than you currently are in. Sorry for the long post just to say if it ain’t broke don’t fix it!
There are a lot of growers unaware that the PH meters need to keep the glass bulb wet with either storage solution or 4.01 PH solution. This will in mild cases cause meter to ‘drift’ and more extreme will crack the glass bulb.
My Bluelab combo meter ran for 3 years without any drift in calibration.
But I got this multi metter that dose both ph and tds now with replaceable tips and a case and extra useful stuff and love it 
