Sponge Filter

This is a weighted sponge filter that uses rising air bubbles to pull water through a porous foam medium. It acts as both a mechanical strainer for debris and a surface for beneficial bacteria to colonise, which helps manage ammonia and nitrite levels in your water.

The unit stands approximately 10cm tall with a 7.5cm diameter sponge, making it appropriate for tanks less than 150 litres. Because the suction is distributed across the entire surface of the foam, there is no risk of small fry or delicate shrimp being sucked into an intake, which is why we usually recommend these for breeding racks.

You will need an external air pump and a length of 4mm airline tubing to run this, as it has no motor of its own. While the lack of moving parts makes it reliable, the constant popping of air bubbles at the water surface can be quite loud if the tank is kept in a bedroom or quiet office.

Cleaning involves pulling the sponge off the plastic weighted base and rinsing it in a container of removed aquarium water. Do not use tap water for this, as the chlorine will kill the bacterial colony you've established in the foam.