What do you have going on with water catchment there? It looks like the rainwater goes to smaller barrel first, but I can't figure out how it then gets to the bigger tank, unless is a valve that you change by hand or something.

Also, love the hand pump on the well. What brand? We are about to install a Bison pump here. Also just working on a 26' x 84' greenhouse...got the bows and purlins up today - it's amazing! Pics to come once I get to it!