Coral dipping can be a great way to prevent pests and parasites from making their way into your aquarium. However, dips can also harm corals if used improperly. The typical concentrated iodine dips are really good at killing most pests, but if a coral is left in the dip long enough it will also die. Fish won’t survive an iodine dip either. So when acclimating your new livestock, be sure to separate fish from corals.