I can't stop thinking about using a toilet flush mechanism for this. It would have the added benefit of a "relief" valve, in the form of the bowl filling tube. Might it be possible to install a one way valve in that tube to keep the discharge tube "primed" with water? I love the solenoid idea, but it makes me nervous to not have a way out if they fail. Suggestions?
And has anyone built one and snapped some pics?