Contains 120ml

Your pH probe is a sensitive glass instrument that ages through everyday use. If you want to improve your Bluelab pH product’s response time and longevity, make sure that you use Bluelab pH Probe KCl Storage Solution - 250 ml to store and hydrate your Bluelab pH probes and pens.  

Simply add KCl solution to the cap of your pH pen or probe for storage after use; make sure to top up the KCl every week. Once a month, you should hydrate your probe in KCl solution. 

You can find detailed instructions on the bottle.