Keeping our tanks and reef environments clean and free of contamination is of paramount importance. It is easy to inadvertently introduce contaminants into your reef environment while performing routine tank maintenance. One way to avoid a mishap is to avoid using tap water when washing out aquarium sponges and other biological media. Components of tap water can kill off helpful probiotic bacteria colonized in the filter media. Tap water can also introduce small amounts of chlorine or chloramine (depending on what your local water municipality uses), unwanted trace minerals and other unwanted trace chemicals into the aquarium. Instead of using tap water, you should rinse the media with water you have collected during a water change. Afterwards, you may discard the water in the normal fashion. This simple procedure will help to maintain a healthy and relatively undisturbed population of probiotic bacteria in your filter media and sponges.