Nano Biological Sponge Filter for Silent Aquariums - Pack of 3 Foam Filters for Betta Fry, Shrimp and Small Fish - Compatible with Nano Aquariums up to 40 liters

Fine sponge filtration: The 3 filters provide mechanical and biological filtration, capturing dirt and waste without sucking up your fish, for crystal-clear water.
Mini size: They measure 5(D) cm x 16(H) cm. Suitable for small aquariums of 20-40 liters. Suitable for raising and feeding various ornamental fish, shrimp, or juvenile fish.
Easy to clean: Each filter can be easily removed for cleaning. Rinse it every 2 to 4 weeks ONLY with aquarium water. Avoid washing it in tap water!
Quiet aeration: Operates at air and does not disrupt your daily life. Push the sponge into the pond so that it completely absorbs the water and sinks to the bottom.
Air pump not included: You need an additional air pump to operate any filter that treats external air to promote oxygen circulation and create a healthier pond environment.