I started some seeds in Ferry Morse Compressed Peat Pellets and in Ferry Morse Sterilized Seed Starter mix on 2/12/2004. Today (2/18/2004), I noticed a whitish, web-like, fuzzy growth on the seed starter mix and on some of the peat pellets. I'm using the rectangular, black, plastic trays with the clear lids that create a humid greenhouse atmosphere. What is this white, fuzzy stuff? Is it a problem? If so, how do I get rid of it?