Collection: Underwater Filters

Filtration With Nothing Outside the Tank

An internal filter sits below the waterline and does its work there. No hoses to leak, no cabinet space taken up, nothing hanging off the rim — which is why these turn up in nano tanks, quarantine tanks, breeding setups and anywhere a canister or hang-on filter is more equipment than the tank warrants. The trade is space: whatever the body occupies is water you no longer have.

What's in This Collection

• Submersible power filters — three sizes, stepping up with tank volume.
• Compact internal filters — small and medium, for nano and desktop tanks.
• An internal water-change filter — filtration plus a drain function in one body.
• Nano corner filters — including a model designed around fry and small tanks.
• Spares — filter extensions and replacement suction cups.

Living With One

• Measure before ordering. A body that fits the corner on paper can still dominate a small tank.
• Aim the outlet along the glass to move the surface rather than blasting the aquascape.
• Rinse the media in water taken out during a change, not under the tap.
• Suction cups perish and let go. They cost little and are worth replacing before the filter ends up on the substrate.