Choosing the Right Automatic Fleece Roller for Your Tank

Quick answer: Choose N-Clear Nano or N-Clear M by your aquarium’s actual filtration layout and confirmed fit first. Then choose the number of filters and whether you need a Main or a linked Extension. Tank volume and a maximum flow rating alone do not confirm that a filter will fit or serve every intake path.

1. Find your tank or sump

Start with the N-Clear tank and sump compatibility directory. Match the exact model, generation and filtration layout—not just the brand or gallon size. Check whether the original sock holder, support blocks or cradle are still installed.

N-Clear Nano

For supported compact all-in-one (AIO) rear filtration chambers. Some Innovative Marine AIO models fit directly; many other supported tanks need a model-specific N-Fit Nano adapter.

Check Nano tanks and adapters · View N-Clear Nano

N-Clear M

For most standard 4-inch filter-sock sump holders and selected larger AIO layouts. A stable original holder, usable space below it and clear access above it are still required. Nonstandard openings may need a specific N-Fit M adapter.

Check M sumps and adapters · View N-Clear M

2. Check the physical fit and service space

• Support and opening: confirm the original holder or the exact adapter supports the filter securely.
• Space below: check the narrowest part of the chamber, including braces, dividers and plumbing.
• Space above: leave room for the motor, a full fleece roll, installation and roll removal. A lid or drainpipe can block an otherwise suitable opening.
• Water path: identify which intakes or sock openings carry water through the mechanical filtration stage.

For M, allow approximately 10.6 inches (27 cm) above the sock plate to the upper, widest roller section, plus extra working space for installation and removal. Body footprint alone is not an adapter or chamber-size specification. For an unlisted or modified tank, use the chamber measurement guide before ordering.

3. Choose the filter count

Use the actual flow through each filtration path, the number of active openings and the system’s bioload. A return pump’s maximum label rating is not the flow through an individual chamber.

For a multi-sock sump, plan which openings will be filtered. An unused opening may need a sock cover to limit bypass; follow the documented layout for your sump rather than copying another tank’s arrangement.

4. Choose Main or Extension

• Main: a complete independent filter system with controller, water-level sensor and power adapter.
• Extension: adds a matching filter and motor to an existing Main. It cannot run independently and shares the Main’s controller, sensor and power supply.
• Main + Extension: two linked filters on the same aquarium system. They advance together when the Main sensor triggers; they do not sense water level independently.
• Two separate aquariums: choose two Main units.

Each filter includes one starter fleece roll. See Main vs Extension configurations and cables for the parts and connection layouts.

Similar names can mean a different fit

• Waterbox 50.3 rear-chamber AIO: Nano with S80120. The older Waterbox 50 Peninsula: M with M1216.
• IceCap 45 and 60 AIO: dual Nano with two S9513 adapters. M is not a supported alternative for these chambers.
• Fiji Cube 20 AIO: Nano with S9089. A Fiji Cube 20 sump with a standard 4-inch sock holder uses the M path.

Before you order

Confirm the filter model, Main/Extension configuration, adapter quantity and service clearance. Buy filters and accessories from the official Nature Dimensions N-Clear store. If the model or holder does not match a documented setup, contact us with the exact model and the missing fit details before ordering.

For installation and operation, use the N-Clear Nano User Guide or N-Clear M User Guide. The Help & FAQ covers shipping, returns and general questions.