Say bye-bye to filter sponges with the Aquascape UltraKlean Fish Aquarium BioBalls. These balls feature a distinctive shape that’s designed to capture waterborne dirt and debris. Their textured surface is ideal for growing beneficial bacteria for a healthier environment. These balls won’t clump together like standard bio balls， and they put in a top-quality performance. They’re an ideal alternative to filter sponges， which clog so easily.