Internal aquarium filter Tetra IN plus IN 800 — internal filter for freshwater tanks, compact submersible unit

Tetra IN plus IN 800 is a compact internal aquarium filter designed for freshwater tanks. The submersible unit delivers combined mechanical and biological filtration using replaceable media cartridges. Engineered to be placed inside the aquarium and mounted submerged, the IN 800 helps reduce visible debris and supports stable water parameters to maintain a healthy environment for fish and aquatic plants. The compact design keeps the device unobtrusive while providing continuous circulation and filtration appropriate for small to medium freshwater setups.

Advantages

The filter integrates mechanical pre-filtration and biological media in a single replaceable cartridge, simplifying maintenance and media replacement. Its compact submersible housing allows flexible placement inside the tank without external plumbing. Quiet operation and low energy consumption make it suitable for continuous use. The unit is compatible with standard aquarium setups and provides reliable water circulation to improve clarity and oxygen distribution.

Suitable for

• Small to medium freshwater aquariums requiring internal filtration
• Community fish tanks with plants where unobtrusive equipment is preferred
• Hobbyists seeking a simple replaceable-media solution for mechanical and biological filtration

Key specifications

• Filtration type: combined mechanical and biological filtration
• Installation: fully submersible internal mount
• Media: replaceable cartridge system with mechanical and biological layers
• Compatibility: intended for freshwater aquaria
• Operation: continuous circulation delivering improved water clarity and oxygenation

How to use

Install the unit fully submerged inside the aquarium according to the manufacturer’s mounting guidelines, ensuring the intake and outflow are unobstructed. Insert the replaceable filter cartridge into the housing before powering the device. Run the filter continuously to maintain water circulation; check and replace the cartridge at intervals recommended by the cartridge’s packaging or when flow decreases. Regular partial water changes and routine tank maintenance will complement the filter’s function.

Usage recommendations

Position the filter where it provides good circulation across the tank, avoid blocking the intake with décor, and replace cartridges promptly to preserve biological filtration. Match the unit size to the aquarium volume and monitor flow rate during initial operation to confirm correct placement.