I potted a bunch of seedlings in spag. over a week ago, now as the spag has dried out, I am starting to see more and more white fuzzy growth on a few of the roots that are sticking above the spag. It seems mostly on the browner or more shriveled roots. Some had damage from the bare root shipping. Should I be concerned about the continuation of this as rot? I ordered some physan 20, should I give them a dunk in that for good measure?