This stuff is a "hydrogel" that takes up large quantities of water, then releases it slowly. It comes as small dry granules. I had purchased some orchids from Windy Hill and noticed several small rubbery clear bits in the potting mix when I repotted them. I asked Marilyn LeDoux about it and she told me she was trying the stuff in an attempt to prolong the interval between waterings. I got the impression that she thought it might be useful, so I bought some from Gardener's Supply. Here's a link for the stuff: http://www.gardeners.com/Terra-Sorb...ghtProofing,14091,default,cp.html?SC=XNET8019
Interesting. I use it in my mud mixes for hoyas - lots of perlite, peat, and some terrasorb or equivalent. That means it's also in my phrag mud mix. I've also been eyeing it as an ingredient for seedling mixes.