I wouldn't wait... I'd get something to zap them now, either Joe's Juice, Aptasia Control, or any of the other stuff out there. As Fluff mentioned, if they get too big, the peppermints won't deal with them. And you have seen how quick they can grow given the right conditions.
Whatever you do, don't physically yank them out. I made that mistake with my first one and had several more to deal with in the next few weeks. You never get it all, and the pieces that float around can make a brand new one!