Purple Goose
New Member
If you are in doubt about the accuracy of your ph meter and are out of calibration solution one quick test that can be performed to determine accuracy is to use vinegar. I did a search for Ph of vinegar on google and wikapedia had a post that vinegar has a ph of 2.4 I did some tests with malt vinegar and white vinegar with a fully calibrated ph meter and what do you know it was spot on 2.4 so if your ever in a pinch to test your ph calibration use vinegar. And as a side not you can also use vinegar as ph down as it is food grade and will not harm your plants also baking soda can be used as ph up .