The Fluval U4 Underwater Filter is engineered to provide exceptional water clarity and a stable aquatic environment for larger aquariums up to 240 liters. Designed with beginner aquarists in mind, this internal filter offers reliable filtration performance, simple installation, and straightforward maintenance.

Advanced Multi-Stage Filtration

The Fluval U4 utilizes a three-stage filtration system:

• Mechanical Filtration captures debris, uneaten food, and waste particles.

• Chemical Filtration uses activated carbon to remove impurities, odors, and discoloration.

• Biological Filtration supports beneficial bacteria growth, essential for maintaining a healthy nitrogen cycle.

This comprehensive approach ensures clean, clear, and biologically balanced water, creating a safe habitat for fish and aquatic plants.

Customizable Water Flow

An adjustable flow control allows aquarists to tailor water movement to suit different species. Whether housing sensitive fish or active swimmers, the Fluval U4 adapts easily to your aquarium’s needs.

Flexible & Space-Saving Installation

The filter can be installed vertically or horizontally, making it ideal for various tank layouts. Directional outlets help distribute water evenly while minimizing dead spots.

Quiet, Energy-Efficient Performance

Operating at only 15 watts, the Fluval U4 delivers powerful filtration while remaining energy efficient and whisper-quiet, ensuring a peaceful aquarium environment.

Easy Maintenance for Beginners

The filter features simple-to-replace media cartridges, allowing routine cleaning every 4–6 weeks without hassle. This makes the Fluval U4 an excellent choice for those new to aquarium care.

Package Includes

• 1 × Fluval U4 Underwater Filter

• 1 × Filter Media Set (Foam Pads, Activated Carbon, etc.)

• 1 × Instruction Manual

Benefits

• Powerful filtration for large aquariums

• Complete multi-stage water purification

• Adjustable flow for diverse aquatic life

• Quiet, efficient, and reliable operation

• Flexible placement options

• Beginner-friendly maintenance system