Seachem Tidal 55 Matrix Replacement Bio Media Maintain a healthy, crystal-clear aquarium with Seachem Tidal 55 Matrix Replacement Bio Media. Specifically sized for the Seachem Tidal 55 hang-on-back filter, this premium biological media provides exceptional surface area for beneficial bacteria, helping naturally remove ammonia, nitrite, and nitrate for a stable aquatic environment. Matrix features a highly porous, inert structure that supports both aerobic and anaerobic bacteria, delivering superior biological filtration compared to traditional ceramic rings or bio-balls. With over 700 m² of surface area per liter, Matrix offers long-lasting performance without needing regular replacement—simply rinse in aquarium water during routine maintenance to remove debris. Each Tidal 55 replacement bag is pre-portioned to fit perfectly in the filter basket, making installation fast and maintenance hassle-free. The Tidal 55 filter is supplied with 250 mL of Matrix media, ensuring optimal biological filtration right out of the box. Features Genuine Seachem Matrix replacement media for the Tidal 55 filter Pre-portioned for a perfect fit in the Tidal 55 media basket High-capacity biological filtration Helps reduce ammonia, nitrite, and nitrate Supports both aerobic and anaerobic beneficial bacteria Highly porous media with over 700 m² of surface area per liter Long-lasting, inert media that will not break down Suitable for freshwater and marine aquariums Keep your Seachem Tidal 55 operating at peak performance with genuine Matrix bio media—the trusted choice for healthier fish, cleaner water, and a more stable aquarium ecosystem.