• Replacement cartridge for the Clearvue 30 Internal Filter
• Provides mechanical and biological filtration for your aquarium
• Switch out sponge once a month

Basic Sponge replacement cartridge for the Clearvue 30 Internal Filter provides mechanical and biological filtration for your aquarium. User-friendly cartridge keeps even the smallest tanks clean. Removes waste, uneaten food, and dirt so your fish stay healthy and aquarium spotless. Make sure to replace the sponge monthly.