These things are great when they work right, however, I have had allot of issues with them so far. The main problem I have had, is that they are vulnerable to overfilling and overflowing (and thus draining your bucket altogether). The ones I have use springs that are probably a little too stiff and they commonly fill to 90% or sometimes even higher. This is too high of a level, as the plastic doesn't hold securely enough and the cup can easily rotate, tip, or sag slightly in some fashion, such that the water starts continuously spilling over the brim of the cup.To fix this, I have resorted to putting small rounded stones in the watering cups. The stones have higher density than the water, and thus the extra weight pre-compresses the spring valve mechanism somewhat, thus preventing the cup from filling as high with water. The chickens however like to peck the stones out of the watering cups, so using somewhat larger and rounded stones seems to work better.Additionally, it appears beneficial to secure the cups to your bucket from two separate locations (not just the threaded part alone), so they are less prone to shifting or changing orientation when the birds bump into them with force enough to otherwise shift them. When the unit shifts orientation, it also easily leads to overflowing situations.Due to the problems with the cups overflowing and draining your bucket from time to time, I recommend having a second/redundant watering mechanism in your chicken coop so that your chickens never run out of water, even if one system malfunctions and fails. I also recommend installing a float valve inside the bucket and plumbing the bucket up to the water mains (or a garden hose spigot), so that the chickens always have water, even if a cup malfunctions by overflowing and trying to drain the bucket.