Well if this guy is right, then yes Kent Tech M is ur fix. If u buy it, buy the gallon. I got rid of mine in a week, i kinda over dosed. Some of my zoos turned pale. But they came back. If all u have is fish, u will be fine
BUT I'm not convicted its bryopsis. I was always under the impression that bryopsis had to be introduced into a tank. Like via a frag or maybe a rock u got from another reefer. I didn't think it could just pop up in ur tank. All ur rock was dry when u started right?