I installed my first 'open loop' living wall today. The red spots are plastic washers used for holding the polystyrene cladding on. Two different approaches for attaching plants - velcro and pockets. The plants are cheap seedlings.

The term 'open loop' is a bit strange, as a loop is by definition closed. What is meant is that water (and nutrients) travel from the fish tank to the grow medium and are there absorbed by the plant. An issue is the steady buildup of salts, I'm hoping that either the rain, or periodic flushing will control this. DC prefers to replace the whole media after each growing season.