I'm looking for an easy way to purify grey water using 2 baths, gravel and plants. I have a couple of square baths, access to bluestone gravel from a forgotton road working site, and I only use grey water safe products. I thought to run the water to one bath, then the next, the baths being filled with gravel, mint, naturally occurring algae, and other plants. Perhaps someone can suggest other suitable plants - I live near Cowra so good frost in winter and hot dry summers. Then the water would empty into a ditch dug across the slope of my orchard, again with gravel, mint and moisture-loving plants growning in the ditch. Any thoughts or suggestions?