Nano aquariums are small, but they still need stable filtration. Because the water volume is limited, changes can happen quickly.
Keep Flow Gentle
Small fish, shrimp, and bettas may prefer lower water movement. A sponge filter can help provide filtration without creating strong current.
Place the Filter Carefully
The filter should allow circulation while leaving enough swimming space. In a 5 gallon tank, every inch of space matters.
Rinse with Tank Water
When cleaning a sponge filter, many aquarium keepers rinse it in old tank water to avoid disrupting beneficial bacteria too much.
Final Thoughts
A small sponge filter can make a nano aquarium easier to maintain when paired with a compatible air pump and regular care.