Sometimes the live rock in our aquariums becomes overgrown with pests and algae. Caulerpa can seem unstoppable and Aiptasia anemones spread like wildfire. No matter what we do to cut back on this expansion, our efforts are usually fruitless and the plague continues. The only way to fully get rid of these unwanted inhabitants is to pull the live rock from the aquarium and use the harshest means. Letting the rock dry out for several days or soaking it in fresh reverse osmosis water are two extreme methods, and some even break out the pressure washer to blast the pests off. Regardless of what method you use, it’s wise to rinse the rock thoroughly and cycle it in saltwater for several weeks prior to putting it back into an aquarium. You might also want to seed the now dead rock with pest-free live rock to reestablish bacteria and other beneficial organisms.