First, it works.
That said, it would seem to work better if you had some pressure in the water line. I have a 55 gallon drum feeding a 5 gallon bucket to maintain the perfect water level for my Alaskan Grow Buckets. The water trickles in instead of rushing in a satisfying toilet tank way because there is so little water pressure created from the barrel. Oh well, lack of visceral satisfaction aside, it still works great after a month of use.
Update 8/2013
Shortly after the first review, the water quick trickling in. I lifted and dropped the float a few times until water started to trickle in again. I've checked on it at least twice a week since then and there have been no further problems.









