Here is a useful tip: I use glass bottles and part of my nightly routine after feeding, changing bottles, checking on everyone and a general straightening up, I go up and down the line and mark the water line on each bottle with a dry erase marker, that way I can check at least every 24 hours that the water line is going down and that each chin is drinking, and how much. It is tedious but it assures me that my chins are indeed getting water as I have found that either not taking water or drinking an excessive amount is one of the first signs of illness. This is a great way for me to monitor my herd. If I can do it with 70 or so chins nightly then it should be fairly easy for a pet owner with one or only a few. The dry erase marker comes off in the dishwasher on a glass bottle, not 100% sure about plastic bottle.