As the tank hadn't been set up for very long, there wasn't much life on and I didn't think in that rock. When I'd treated my hair algae with a lesser strength of H2O2, like 2 or 3%, it didn't kill it. So I thought I'd just go full strength, and used gloves and goggles while dealing with it. When I saw bubbles coming up from the rock after I put it back in the tank I should have realized it still had H2O2 in it and taken it out immediately. It may very well have ****ed off my Palys even, which then proceeded to juice my tank in self-defense...