@jaj @jaj That would probably work if you have something like a downpipe or something to collect the water from a wider surface. I already have a kinda daisy chain at the bottom.
Linking the bottoms back to the next top is tricky because it’s gravity-fed. They’re all communicating vessels, so you need to take into account the water levels, and potentially break the link with air intake. But I don’t think you can bring water back up with so little pressure.
FWIW, it seems like the reservoir also refil nicely with heavy rain on the beds.