The white baskets that come with AeroGarden seed pod kits can be reused in both AeroGarden and for other hydroponic methods, such as Kratky (non-circulating), DWC, etc… I’m often asked where to find those, and the sponges I use.
The AeroGarden baskets are essentially 1.5″ net pots. I like them because they don’t take up a lot of space, and can fit a hole cut with a 1.5″ hole saw. You can find them at the AeroGrow website, eBay or Amazon. Amazon usually has the best prices, but it pays to shop around in case one or the other has a sale. If you need larger than 1.5″, traditional net pots can be used. they typically range from 2″ size up to 10″.
When using the AeroGarden baskets I prefer the Park Seed Biodome sponges, but the AeroGrow sponges, like what come with the seed pod kits work fine. The Biodome sponges are cheaper. For larger net pots, you might want to look at Rapid Rooter plugs (or similar) or rock wool.
Additional supporting medium
If your sponge doesn’t fill the net pot, you’ll need to add some supporting material to fill around the sponge in the net pot. I use both clay pebbles and coco coir chips. Both are light and airy and all the roots to move through them easily.