Hanna InstrumentsHI 70300M Storage Solution for pH/ORP Electrodes, 230mL Bottle

Use it to store any of your pH or ORP electrode probes. It works, not much else to say.Most electrodes come with some type of sponge soaked with this solution but peopledon't replace it when they store the electrode. I use this for the sponge that comes withthe pH probe electrode on my Hanna portable pH probe. Keeps yours electrode in good working shape.

I've ordered this before for use on my pH meter - they're expensive and well worth taking care of - and I've reordered it at least once, since, and will again, I'm sure. Excellent product!

Works fine. Casual user and this will last several years I think.

The solution helped me store my tester and keep the sensors clean

Not much else to say.The product works, and for me this is a lifetime supply.I put a couple drops on a small piece of sponge and put the sponge in the lid of my meter. Then, when closed, the tip is in contact with the solution.

This is the product that Hanna recommends for their HI 98121 combination pH/ORP meter so that's what I got. Whichever pH probe you have, use the solution the manufacturer recommends. 9 times out of 10 you can get away with a storage solution from someone else but at the price of pH meters you don't want to be that guy who was the 1 time in 10.

I was instructed I could use either ph 4 solution or storage solution to keep my meter in good working order. using ph 4 was a mistake. This stuff works great.

Unfortunately, it evaporates quickly leaving massive amounts of salt behind. Haven't re-used my pH meter since storage. It will be interesting to see if it still works.