When I found I was losing water from my bubble counter, a Milwaukee one that looks like the photo, I finally discovered that the water was leaking out at one of the O-ring seals on the clear tube. I discovered it by noticing that the area under the bubble counter was always damp. I tried everything I could think of to stop the leak, but finally gave up and removed the bubble counter in favor of one I made myself. That one held water for months at a time. Since then I have been suspicious that those who have to replace the water once a week have that same kind of leak.