Chickens dont like clean water. Seriously. Mine qouks rather drink out of a shrinking warm stagnant rain puddle at the end of the driveway than drink out of a clean fountain.
Mine too!! And when I dump the gross dirty water and refill it with fresh, they try to drink out the mud/poop puddle newly created!!
I try to shoo them away cause I don’t want them to get sick, not that I don’t clean the run but just ew, but they would rather drink out of that gross little dirty puddle than the fresh clean water I just put in the waterer. 

