Bio-ceramic rings are an essential filtration medium for every aquarium. They can effectively eliminate odors, remove harmful metals, and purify and soften the water. Directions Wash thoroughly before use to remove fine dust from handling. Place them directly in the chamber or in a nylon filter bag. Maintenance They should be washed monthly using water from the aquarium. Never wash them with tap water or any water that may contain chlorine; always try to use water from the aquarium. The ceramic ring should be replaced every 6 months, and do not replace all filtration media at the same time. Schedule media replacement to ensure stable bacterial colonies.