Sponge filters are the unsung hero of the hobby — cheap, gentle, and impossible for tiny shrimplets or fry to be sucked into. Powered by nothing more than an air pump, they provide excellent biological filtration with a soft flow, making them the go-to for shrimp, betta and breeding tanks. This UK guide covers the best sponge filters in 2026.
Here are our picks and how to set one up.
- Sponge filters are gentle and fry-safe — ideal for shrimp, betta and breeding tanks.
- Powered by an air pump, they provide excellent biological filtration with soft flow.
- Run one in your main tank to instantly cycle a quarantine or hospital tank.
- Clean by squeezing in old tank water — never under the tap.
Why sponge filters are special
Their gentle flow won’t shred a betta’s fins or trap fry, and the sponge itself becomes a vast home for beneficial bacteria — plus a grazing surface shrimp love. They’re also the perfect thing to run in your main tank, then move to a quarantine or hospital tank for instant cycling.
Our top picks
Best overall — dual sponge filter. A sponge filter with two sponges gives more surface area and lets you clean one at a time to preserve bacteria.
Best for nano/shrimp — mini sponge filter. A mini sponge filter suits small tanks and shrimp colonies.
Complete the setup. Add an air pump, airline tubing and a non-return valve.
Setup and cleaning
Connect the sponge filter to an air pump via airline, fitting a non-return valve so a power cut can’t siphon water into the pump. To clean, simply squeeze the sponge out in a bucket of old tank water — never under the tap, as chlorine kills the bacteria. Clean only when flow drops, and if using two sponges, clean them on different weeks. See our air pump guide.
Frequently asked questions
Are sponge filters good?
Yes — they provide excellent biological filtration with a gentle, fry-safe flow, making them ideal for shrimp, betta and breeding tanks. The sponge also houses masses of beneficial bacteria.
How do you clean a sponge filter?
Squeeze the sponge out in a bucket of old tank water until the water runs clear. Never rinse it under the tap, as chlorine kills the beneficial bacteria living in the sponge.
Do sponge filters need an air pump?
Yes — most sponge filters are driven by an air pump connected with airline tubing. Fit a non-return valve so a power cut can't siphon tank water back into the pump.
— Jaqline Smalling, FishForever
Leave a Reply