Get the Most Out of Your New pH Pen!


We want you to get the most life out of it, so we’ve pulled together some usage and care tips. 

Usage & Care Tips

pH pens age quickly through normal use. Following these care steps will help you maintain accuracy and improve the life of the pH pen: 


  • Hydrate the Bluelab pH Pen for 24 hours in KCl storage solution before first use. 
  • Always keep the pH probe tip wet. If it dries, it dies! 
  • Rinse the pH probe tip in clean tap water between readings for accuracy. 
  • Always place the storage cap back onto the pH pen after use. 
  • Add 3-5 drops of KCl storage solution to the round hole of the storage cap every week. 
  • Clean, hydrate and calibrate the pH pen every 30 days. Do this when the CAL check mark disappears. This improves accuracy and reading response speed. 
  • Only use plastic containers when cleaning, hydrating and calibrating. 
  • Touching the glass bulb with your fingers will contaminate the glass. 
  • Never plunge a cold probe into a hot liquid (or vice versa). Sudden temperature changes can permanently damage the pen. 
  • Do not immerse in oils, proteins or suspended solids that will leave a coating on the glass bulb. 
  • Never drop or knock the pH pen, the glass bulb will break
  • Never store, rinse or soak the pH pen in RO (Reverse Osmosis), Distilled or Deionized water. Pure water changes the chemistry in the reference, causing the probe to die.


For more detailed care instructions, continue reading below.


All glass electrodes have a bulb and reference junction that must be kept hydrated. pH glass is unique as it forms a gel layer when properly hydrated which interacts with your sample and buffers. As an electrode hydrates their behavior shifts - therefore it is important to start and end calibrations and measurements with a hydrated electrode. 

  • Hydrating the junction ensures a connection between the internal electrolyte and the sample. Without this connection, the electrode can be slow to respond and have poor stability.
  • To minimize junction clogging and ensure fast response time, always keep the glass bulb and the junction of your pH electrode clean and hydrated.
  • Using a storage solution helps to maintain the reference electrolyte concentration
  • Damage due to accidents, misuse, tampering or lack of prescribed maintenance is not covered.
  • Calibration is only as good as the buffer being used. The pH buffer values change over time once the sachets are opened. Fresh buffer should be used for each calibration. 
  • The probe should be rinsed with purified water each time before placing it in the buffer or sample to be tested.
  • When the meter is not in use it is important to add several drops of storage solution to the protective cap to keep the probe hydrated. If a storage solution is not available, a pH 4 or pH 7 buffer can be used.
  • For improved accuracy, it is recommended to calibrate to a minimum of two points. It is important to use buffers that bracket the expected value of the sample to be tested. For example, if the expected value is pH 8, the meter should be calibrated using pH 7 and pH 10 buffers.
  • It is important to calibrate and measure samples at the same temperature. A dramatic change in temperature between buffer solutions and samples to be tested will give inaccurate readings.