I have two 4 gallon waterers that I switch out each day. The handle is a lid that I take off and rinse out the plastic/poly water holder with. The bottom part is snap on, red in color, and comes off for easy cleaning. I have 35 chickens. The big waterer is in the chicken house, but I put a small one gallon waterer outside also.
It is "plastic" too. the kind you have to fill up, put the top on and flip over.
I don't like the galvanized waterers, they eventually rust.
I add 2 T Apple Cider Vinegar per gallon of water every day to their drinking water, good for them, and keeps the waterers from getting too scummy. Don't give your chickens any water you wouldn't drink yourself, altho, I realize they can "scratch" and get dirt into the waterers, but if you change it out everyday, all will be well......
Hope this helps,
DonnaBelle