Blotfish Biochemical Sponge Filter for Aquariums

If you are dealing with cloudy water or low oxygen in a small to medium freshwater aquarium, this double sponge filter provides a low-tech way to improve circulation and water clarity. As an air-driven aquarium filter, it increases surface area for beneficial nitrifying bacteria and supports oxygenation and gentle water movement in tanks up to 150 litres.

The double layered ribbed sponge structure offers more surface for bacteria, which helps a tank cycle faster and maintain clearer water. Three removable media containers accept ceramic bio media to add biological filtration capacity and assist removal of dissolved waste. The sponge also performs mechanical filtration by trapping larger particles, while an adjustable exit tube lets you direct flow and set height to avoid disturbing plants or delicate species. Simple to install using an airline and air pump (not included), it comes with suction cups for secure mounting and is especially useful for shrimp, betta, breeders and fry where low flow and strong biological filtration are desirable.

Key Features

• Double-layered ribbed sponge – increases surface area for beneficial bacteria and supports faster cycling
• Three media containers with ceramic bio media – adds extra biological filtration to reduce dissolved waste
• Mechanical filtration and bacteria colonisation – traps larger particles while supporting colonisation of nitrifying bacteria
• Adjustable water exit tube – allows you to control flow direction and height to suit plants and delicate stock
• Air-driven installation with suction cups – easy to fit using an airline and air pump, ideal for breeding and shrimp setups

Frequently Asked Questions

Is this filter suitable for shrimp, betta and small community tanks?

Yes. Its double layered ribbed sponge and ceramic media support beneficial bacteria and gentle flow, making it suitable for shrimp, betta, breeder, fry, goldfish and similar tanks up to 150L.

What tank size does this model support?

This S-size model is designed for tanks up to 150L. Confirm your aquarium volume matches this capacity before fitting the filter.

Do I need an air pump and how is the filter installed?

Yes. Attach an air hose to an external air pump (not included). Fix the filter inside with the supplied suction cups and aim flow using the adjustable exit tube.

How should I care for the sponge and media to keep filtration effective?

The double layered sponge traps larger waste and supports beneficial bacteria; regular maintenance is necessary to preserve filtration performance.

Is the filter easy for beginners to set up and does it come with a warranty?

Yes. Simple to install using an air hose connected to your air pump, includes three suction cups for mounting and has a two year warranty.

Check the recent prices for Double Sponge Filter for Aquariums Up to 150L below.