I used the soil I buy in bales that the nursery uses for their seedlings, so it isn't potting soil - uh, I don't think. I will double check. And I will re read my instructions. Hmmmmm. Especially the thing about the airspace. That is provided by the upside down basket at the bottom, right? As the water is absorbed or drained it keeps the soil up out of the basket. RTFM I guess. Opppsss. My engineer husband's vernacular pops out sometimes.
