Farm Tuff Top Fill Poultry Fountains, 5-Gallon

I absolutely LOVE this waterer, it's the only one I use!
I got a 3 gallon one of these for my first flock, it lasted at least 6 years, it finally broke from being sun rotted. If kept out of the sun it will last a very long time! The durability is amazing.
For a medium sized flock or less, this doesn't need to be filled every other day or so. I use 3 of these for my current flock of 15, and on average only fill them once a week. But, I do tip it over to get all the water out of the red tray, cause it will get a bit dirty, at least for me. It does make the water go by faster, no big deal though.
It's so easy to fill, and it has never ever leaked.
It is hard to clean inside, which can be annoying. If kept out of the sun though, you won't have to deal with much cleaning. That's really the only con for me.

Have used this model for several years. Is a little heavy to haul when full. Very durable.
Only draw back is it needs cleaning often to keep algae and mosquitos from breeding.

Anyone who has raised chickens and uses water founts knows the struggle of finding a good waterer that does not leak. I've used these waterers for nearly 5 years, and they are almost completely leak-free. Once you tighten the lid correctly, the waterer's vacuum system holds the water at the proper level; you don't have to place it on precisely level ground like some bell-style waterers. 5 gallons of water is enough to last a small flock for over a week, although it can get heavy to carry. The material is tough, doesn't crack, and can put up with a lot of wear and tear--I'm still using the first one I bought 5 years ago.