I use 1 quart mason jars for the top & just buy the reservoir bottom- and the mason jar is heavier so it doesn't tip. It's better for very young chicks (first few weeks) as they can't reach into the reservoir in the larger ones as successfully. I also raise these up a bit on a piece of 2x4 (that extends past the bottom so chicks can use that as a step until they're tall enough to reach over the lid- this keeps it elevated from the wood chips so they don't go in as easily. Plus these are easier to refill and wash than the huge ones that spill all over when you flip them around. These are great for short term use, esp with smaller flocks unless you get several to put throughout the brooder.