Atlas Scientific pH/ORP Electrode Storage Solution 250ml (8oz)

Good value/mL. I bought 4 of these for my lab techs and will buy again when I run out.

I bought a cheaper Gain Express ORP meter and I just keep the meter tied to an upright support of a book shelf with this solution in its end cap with the cap side own. Keeps the sensor constantly emerged and running fine.

Worked as it should

Amazon is a quick and easy source for the Atlas PH solutions and I use the 4.00, 7.00 and the storage solution. You should regularly calibrate your PH meter with quality solutions as it will drift over time as the electrode ages. This solution is used to store the electrode when not in use as the probe needs to stay wet or it becomes inaccurate and eventually unusable if it is stored dry. This solution works well, although once opened and stored over a long period of time, somewhere in the 12 month area the solution will begin to grow some sort of mold or bacteria. This would be true of most neutral fluids and is not a fault of the solution itself. Just know that once opened to keep an eye on it and replace it once it starts looking dirty or funky.

This is a must have if you have a nice ph pen that you want to take care of.