Mechanical Filtration: The mini aquarium sponge filter can effectively trap debris, food residue, wastes or other impurities in water. Prevent them from entering the aquarium to keep water clean. Deep Cleaning: The build-in mini filter balls are helpful for blocking large particles in the water and accumulating beneficial elements. Provide biological filtration to fully remove excess damaging substances. Small Internal Filter: 2.13" W x 2.4" H. Fit for fish tanks up to 5 gallons. Suitable for the breeding and feeding of various ornamental fish, shrimp or fish fry. Detachable Submersible Filter – required air pump: < 2 W; jetting volume of air stone: 0.6 L/min. The bio sponge filter with air stone can produce a cascade of dense bubbles in the water, greatly promoting oxygen circulation to keep your fish healthy. Easy to Clean: The bio sponge filter can be easily detached for cleaning. Rinse the sponge every 2 to 4 weeks with aquarium water ONLY. Avoid soaking or washing it in tap water! Replace the white sponge every 2-3 months! Aquarium Small Fish Tank Filter for Breeding Fry Betta Shrimp Tanks