Is there such a thing as a reliable automatic watering device?

[martinliss]

I have four hens. I've tried at least 3 different devices all of which attach to a garden hose and contain a float valve that's supposed to allow the container to fill the water container to a certain point and then shut off. All have worked for a few weeks and then for some reason the float valve no longer completely shuts off the water causing it to slowly overflow. Thinking that it might be my outside water pressure I installed a 15 PSI valve but it did not help. Does anyone have any suggestions or advice?

 

[Willowspirit]

Following

 

[Cyprus]

Is it possible that something is clogging the float valve? Do you have hard water?