We are experimenting with a graywater "system" to help us use our water more efficiently. So far, it consists of a bucket under the kitchen sink where the used water drains. A spigot was recently added to the bucket so that we can move the bucket outside, attach a hose to it, and let gravity water our gardens. We would like to connect the top of the bucket back to the drainage pipe so that we don't have to worry about the bucket overflowing.
Ideally, the system would involve some sort of pump so that we don't have to move it outside to water the garden. Perhaps we can build a solar powered pump to accomplish this.