Several years ago I dug a HUGE DEEP hole in the center of my back yard, lined it with scavenged carpet, then with the liner for an 18 foot diameter above ground pool I got on Craig's List for $20. I took two scavenged plastic milk crates, tied a swimming pool noodle to the top of each, then packed them with Louisiana iris and hot water cabomba,...this made them floating water purifiers. Goldfish controlled mosquito larvae. I could swim two lengths, and the depth was up to my lower chest. But in time the sides starting slowly pushing in, making it smaller and smaller. So I then added more water plants, pond snails, and Golden Apple snails which I harvested and ate for years. But last year I went in, punctured the sides about two feet from the bottom with my machete to set it up to evolve into a gigantic "Water Wise Containter Garden" that will support one 'Raja Puri' banana and one 'African Rhino Horn Plantain' once I fill it with logs, bags of leaves, plus the sand from a smaller, similarly lined pit I am digging soon a few feet southeast of to grow my guava in. The pic is of the west end from when it was a wonderfully ecologically balanced Golden Apple snail pond that helped to meet my protein needs. Each winter I grew arugula and various brassicas all around it. Cool to be consciously evolving it into a third incarnation!