I board the unit. It is rather quiet, we only heard a little zoom, this is very very light. We put it in the living room and the zoom is not disturbing at all, it goes unnoticed. Parcontre when it is no longer sufficiently filled, then he made a fool of noise, so you fill it in time (= 1x week). Easy to clean, I put water bottle to avoid to have too much limestone. Cleaning every 3 weeks, for me that's enough. My cat is drinking much more since that it has its water fountain. So not hesitate! Buy!
