I have calibration liquid, but still do a side-by-side comparison with my old stand-by...the (liquid) aquarium water ph test kit. ($6.00) I test the water with my ph pen, then test same sample of water with the test kit. Gives a good idea how close your pen really is. :thumbsup:

I just checked...drain opener has a ph of 12.
Household bleach is a 12.5
Baking soda, 8.4

The MSDS HyperGlossary: pH

A ph of 12 just doesn't seem likely, tho. Even a high-range ph test kit for saltwater aquariums only goes up-to 9.5 or 10.
If your city water is 12, call a lawyer. If you have your own well, and it's at 12...you'll want to look elsewhere for your water.