anyhow on with the show...
Step 1: Hardware you'll need
A garden pond pump (the more powerful the pump the higher you can build your garden.)
Some aquarium air tubing (it's cheap enough so just buy a little roll and stash what you don't use.)
Some assorted nuts and bolts
A cheapo washing line
Growing medium (I've used clay balls before but here i'm using perlite)
Some plastic wire mesh ( the amount you need depends on how many levels your garden will be)
Some black plastic rain guttering (it doesn't have to be black but i figure black does a decent job of absorbing heat and so will heat the plants nutrient solution slightly, again how much guttering depends on how high you want your garden)
A couple of U nails to hang your garden from.
A wall that gets plenty of sun. (the size of the wall and power of the pump will determine how high your garden can be)