Bluelab KCL storage solution 100ml

Bluelab potassium chloride solution for storing pH electrodes. Keeps the glass membrane hydrated so your probe stays fast and reliable.

Three storage situations, three answers

"Store it wet" is the advice you see everywhere, but there are three different situations in practice, and they do not ask the same thing.

Between two readings on the same day. Here rinsing matters more than storing. Rinse the tip with clean water so nutrient salts do not dry onto it, and leave it in its cap. The probe never gets time to dry out.

Between readings across a week, or between crops. This is what KCl storage solution exists for. A few drops in the protective cap keep the membrane in the state it should be in. Check occasionally that there is still liquid in there: a cap that has leaked dry is exactly as dry as no cap.

Long storage, months. Same principle, but check more often. This is where most probes die: it goes into the cupboard and comes out a season later, sluggish and beyond calibration. Set a reminder, or keep the probe somewhere you will see it.

Why not just water? Tap water will do temporarily, deionised water certainly will not: it is ion-poor and therefore pulls ions out of the membrane. You slowly rinse away what makes the measurement possible. Rinsing with clean water is fine; storing in it is not.

For pH electrodes only. A conductivity probe has no membrane to dry out and can go away dry once rinsed.

Technical Specifications:

• Type: potassium chloride storage solution (KCl)
• Volume: 100 ml
• Brand: Bluelab
• Use: storing pH electrodes
• Not for: calibration. Use pH 4 and 7 buffer for that

Frequently asked questions

Does this suit any pH probe?
Yes, every glass pH electrode wants storing wet: including other brands.

My probe has been dry for months.
Stand it in KCl storage solution for a few hours, then calibrate. If it calibrates again, it is back. If not, it is finished.

How often do I top it up?
Only when the cap runs dry. A 100 ml bottle therefore lasts a very long time.

Can I use buffer if I have no KCl?
As a stopgap, pH 4.01 beats water. But KCl is what the membrane was designed for.