my henna ph meter.

my meter started going up on the scale. when I tried calibrating it, it would not go below a certain point. I had this happen before, and replaced it. I took the old one, and its fine now, after months of setting. I wonder, if my nutes "gum it up" as it were. I soaked them in peroxide for 15 minutes. any other ideas? the darn sensors cost 40.!

I keep my probe stored in a 7.0 calibration solution and so far, no problems, they also sell a storage solution.