Maintaining Your pH Meter



While pH probes do not last forever, proper care and storage will ensure a long life of accurate measurements. Maintaining your probe involves three simple tasks: calibration, storage and cleaning.

Initial Use

Before you can first use your pH meter, the probe must be hydrated. Place the probe in water for 24 hours then calibrate.


The accuracy of your pen is only as accurate as the reference solution used to calibrate!

To calibrate your probe first rinse off the probe well. Place the probe into the 7.0 calibration solution and wait at least a minute or until the reading steadies. Calibrate and rinse well. Repeat with the 4.01 calibration solution.

Never calibrate directly from the bottle. Doing so will contaminate your stock solution.


Remember: If the probe dries, it dies.

A dehydrated probe is the leading cause of failing pH meters. A dehydrated probe is also the easiest problem to combat. When you are done using your pen, rinse well. Fill the cap with enough storage solution to cover the probe and recap. Storage solution is recommended but tap water may also work, check your manual.


Most sources recommend cleaning your probe before each calibration. This practice is usually unnecessary if the probe is rinsed well after each use. If you do notice that your meter is not reading as quick as it used to, a good cleaning may be due. For more information on cleaning your probe check your manual.

  • Do not use the probe to measure distilled, deionized (DI), or reverse osmosis (RO) water.
  • Do not use your probe to measure organic solutions, proteins or oils.
Doing so will void most warranties and may cause permanent damage to the probe.

Have any tips for pH meter maintenance? Drop a line in the comments below.

Related Product: Bluelab Maintenance Kit

Flo-N-Grow - February 04, 2013

Hey James thanks for the link!

James Moore - January 22, 2013

Sounds good. Hats off to you for showing the steps to maintain and monitor pH meter. I have found a very interesting guide which shows us How pH probes work and how to avoid pH level problems in your hydroponic garden at

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