Definately agree on the false sense of security. I had issues with my electronic temp gauge and my ph meter. I found the ph meter gave false readings once the battery started to get a little week. Took awhile to figure that out. Then with my temp. gauge I noticed it started reading kind of low. When I tested it with a good old glass thermometer, I found it was over 12 degrees off! My tank was getting way too hot. Fortunately I discovered this before it went too long.