It doesn't have touch screen buttons. Hold your finger over them for a couple seconds. Also mount, so screen is at 45 degree angle. This leaves a set of pins at the bottom of pipe. And make sure you have a straight section of pipe 10 times longer than diameter in front and behind meter.We couldnt get a very accurate rate with glyphos - gave up on it. Also had a very difficult time powering it up. Touch screen never wants to wake up! Still use chem handler.