I couldn't wait to try it. I opened up the package and couldn't waste the precious time getting sample water. No way. So I dropped the pill in the empty tube and nothing happened. I changed the batteries and nothing. I pulled it apart and checked the soldering and nothing.I was bugging out

Then in a stroke of genius (too little too late as ALWAYS) I thought I should try it like I was testing for real and that worked fine. I still have the red mark from the facepalm.