Do you have any wicking garden beds? What do you plant in them?
I've been given large fibre glass garden beds with the aggregate, piping, geofabric and and good quality soil (mainly composted organics). The vegetables that grew in them were huge.
Some of the planters had blue metal aggregate; the others had "less expensive alternative to blue metal" aggregate made from recycled concrete. The blue metal sells for $78/tonne; the recycled concrete $47/tonne from Bunnings.
I'm inclined to replace the recycled concrete aggregate (to avoid the possibility of contamination, but that would mean the soil - which is great); what are your thoughts? What have you used for your garden bed?
What about the geofabric? Did you buy your soil or make it yourself (e.g. hot compost)?
I haven't completed it yet, but I'm in the process of building one using milk crates as a frame to support the soil layer, rather than blue metal or whatever filler material. This cuts down a lot on cost, and increases greatly the amount of water your reservoir can actually store, because it isn't full of rocks. I'll then use strips of hessian running down into the water as wicks.
Got the idea from here https://www.savoursoilpermaculture.com.au/blog/wicking-beds