• Mycarbumps: Small fish nets.
• Tailwheel: Buy a package of small plastic cups and burn holes in them using a soldering iron.
• Mhayek: Devise a collar: after cutting holes with a hole saw in a plastic tub, pieces of packing foam are cut into round pieces to fill the holes. They are cut with a slit from one side into the middle. Then take a cutting of a plant, slip into the slit, and put it into the hole with about 1 inch below the water.