Are ph reading is way off compared to are Controller reading. I found out that the Chemical co. is putting distilled water In are storage solution bottle giving us readings that are way lower than actual. After rinsing out three times and Checking ph it would read low. In about 1\2 hour with the sample still in there It would read where it is supposed to be at. Do not use distilled water as a storage solution like they say in the manual,it will save you a lot of head ache.Use the recommended storage solution That it says in the manual.