A collections of multibin inserts featuring drainage holes on the bottom and holes in the sides to let water in or add aeration.

When I first saw the whole shells and inserts concept, I was immediately reminded of those self-watering planters people use for african violets and the like. These inserts fully realize that idea by adding holes all around the sides. These could be filled with leca (or another hydro medium) and added to a hydroponic flood tray fitted with multibin baseplates, or simply used to keep plants in a semi-hydro setup. The 1x1 inserts can make excellent aerated starter pots for seedlings or cuttings.