watering cups not filling

[emchick53]

My chicks are about 4 months old, we finally got our watering system up and running. We have 4 watering cups attached to a PVC pipe.
They seem to drink the water, but I guess their beaks aren't hitting the trigger to fill it up. Any help? How do I show them what to do? Its getting pretty hot out, I want to make sure they have their water! Thanks!

 

[RedRoosterInn]

I just installed the same type of water system hope somebody has some suggestions

 

[Sassysouth]

I have been using them for a few days and my husband says he saw the chickens using them (I have not). When I fill the cup up, pecking the yellow piece with my finger, they are so thirsty. I am thinking of going back to my regular waterer.

I know the cup just distrubutes a small amount of water. But my chickens are acting like they are really thirsty.