Cascade 150 & 200 Bio-sponge 1pk Replacement. Ensure your aquarium stays crystal-clear and healthy with the Cascade® 150/200 Bio-Sponge 1-Pack Replacement. This essential aquarium filter sponge is specifically designed for both the Cascade 150 and Cascade 200 Power Filters, providing superior biological filtration to maintain a thriving aquatic environment. It effectively traps debris and offers a large surface area for the growth of beneficial bacteria, which are vital for breaking down harmful waste. This easy-to-replace filter media helps keep your fish tank clean and your fish healthy with minimal effort.