I have written several articles about building cheap wicking beds using mixed materials and lined with builders plastic to form a reservoir. Unfortunately, these beds simply do not last. The builders plastic develops a leak, roots get in, and the reservoir fails. I am trialling a bed using pond-linear (which is quite a bit thicker), however experiments with a reed-bed made with pond-liner (it leaked!) suggest that this is unlikely to work.
For now, I am transitioning my leaking wicking beds (I think three of four are leaking) to IBCs, which I am hopeful will have better longevity. I will document this more in future.
