It looks like I'm a bit late to the party, but it looks to me like what's called cobweb mold! It's a common problem with mushroom grows, but I have never seen it with cannabis. I really can't tell though from the pics. Could be mycelium, the underground growth of mushrooms, in an early state as well like many others have already pointed out. Who knows, maybe you'll get a few mushrooms pop up! Since you have already made your transplant, just keep an eye on it. If it's mycelium, it's good, if it's cobweb, it's bad.