Waterers can be made just like the feeders.(PVC) My waterer looks just like my feeder but the cap at the top is sealed. When I fill it up with water an then stand it up the water it trapped because no air can get in.
I have one that I made from a 1 qt heated dog dish and a gallon jug. I wrapped the jug w/ a 9 ft pipe heat tape, and made a wire harness for it so it hangs upside down in the dish. if you don't need heat, it would be even easier.