N-Clear M Manual

N-Clear M Fleece Roller Filter - User Manual
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Introduction

Product photo of the N-Clear M filter.
N-Clear M filter product photo.

The N-Clear M Filter is a patent-pending automatic filter that fits most 4" filter sock sumps and many popular AIO systems. This automated, high-efficiency filtration system helps keep your water crystal clear with minimal effort. Free N-Neon 3D fluorescent stickers included.

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Key Features

  • Automatic Roller Filtration: High-density fleece advances automatically when clogged, providing continuous mechanical filtration with no manual intervention.
  • Industry-Leading Compatibility: Patent-pending fitting system designed to work with most 4" filter sock systems, with no modifications required.
  • Flexible Adapter Support: With N-Fit M adapters, also compatible with many systems with filter chamber openings larger than 4" x 3.25":
    • 7" x 4.5" rectangular filter sock systems
    • Many AIO systems
    • See the full list in the table below
  • High Flow Rate: Rated at 800 GPH in single mode or up to 1600 GPH in dual mode, suitable for tanks up to 120 gallons.
  • Dual-Mode Support: Allows two filters to operate synchronously using a single controller, ideal for multi-filter-sock sump setups.
  • Sensor-Based and Timer Modes: Supports sensor-based mode and an experimental timer mode. Sensor-based mode advances fleece in response to real water level changes. Experimental timer mode advances fleece on a fixed schedule without sensor input.
  • Plug and Play: Fully pre-assembled out of the box. Simply plug in a few connectors and start running within minutes.
  • EasyThread Fleece Installation: Innovative EasyThread installation method enables fast, clean fleece loading with minimal handling, making replacement simple and frustration-free.
  • Freshwater and Saltwater Ready: Designed for reliable operation in both freshwater and marine environments.
  • FDA Food-Grade Fleece Rolls: First in the industry. The fleece is made from food-grade material and independently tested by a certified third-party lab to meet U.S. FDA food-contact standards (21 CFR 177.1630).
Note:
  • Minimum required clearance above the filter sock plate: 4" x 3.5" x 9.8" (102 mm x 90 mm x 250 mm). Please make sure there are no cables, pipes, or valves interfering with the clearance above the filter sock opening within this required space.
  • The extension filter must be connected to a main filter. It does not include a power adapter, controller, or sensor. A dual-link cable is included, and all connected motors advance together when the main sensor triggers.

How Automatic Filters Work
(Demonstration: N-Clear Nano)

Quick overview of the N-Clear M fleece roller filter in action.
  1. Water Intake: Flow from the aquarium enters the roll filter and is directed across the fleece.
  2. Filtration: Suspended debris is captured by the fleece while clean water exits the chamber.
  3. Sensor Detection: As debris accumulates, flow slows and the water level rises until the optical sensor is triggered.
  4. Automatic Advancement: The motor advances a fresh section of fleece, restoring flow and lowering the water level.
  5. Continuous Operation: The cycle repeats, providing uninterrupted mechanical filtration.

Installation Instructions

N-Clear M installation video.

Components Included

Components included with the N-Clear M filter.
Components included with the N-Clear M filter.

Dual Mode Setup (Optional)

The N-Clear M Filter supports Dual Mode, allowing multiple filters to share the same controller and work together for tanks with multiple filter chambers. All connected motors advance together when the main sensor triggers.

Use the included splitter cable to connect the motor of the secondary filter to the motor connector on the primary filter's controller.

Note: The secondary filter does not require a separate sensor.

Water Blocker & Bypass Check

The water blocker helps seal the sock opening so water is directed through the fleece instead of slipping around the filter. Before tuning the sensor, confirm the correct water blocker is installed and seated high enough to reduce bypass.

  • If you see a gap or too much bypass while using the shorter/lower water blocker, switch to the taller water blocker to seal the opening better.
  • In multi-sock sumps, also check unused sock openings or covers. Water that bypasses through an open sock hole will not be filtered by the fleece and can make one roll stay much cleaner than the other.
Diagram illustrating two N-Clear M filters connected to a single controller in Dual Mode.
Dual-mode wiring showing two filters sharing one controller.

Adjust Sensor Height

Set the sensor height after installation so the filter advances only when the fleece begins to clog. The goal is to keep the optical sensor above the normal clean-fleece water level, then let the rising water level from dirty fleece trigger the first roll.

Recommended Adjustment Method

  1. Start high: Set the sensor to its highest position.
  2. Wait for the fleece to get dirty enough: Run the filter for about 12 hours, or up to 24 hours for tanks with a light bioload, until the fleece darkens and the internal water level rises significantly.
  3. Lower the sensor gradually: Lower the sensor a little at a time until the sensor tip just touches the water.
  4. Confirm the trigger: Wait up to 40 seconds. The motor should trigger, the fleece should advance, and the water level inside the filter should drop as clean fleece replaces the dirty clogged fleece.
  5. Keep that height: The point where the sensor first triggers properly is the optimal sensor height.
Fine adjustment: Move the sensor in small increments, then give the filter time to respond before moving it again. Raise the sensor if the filter advances while the fleece still looks clean. Lower the sensor if dirty fleece builds up and the filter does not advance.

Controller Guide

Front view of the controller with labels for buttons and LED indicators.
Controller front panel with labeled buttons and indicator lights.

Buttons & Manual Controls

MODE Cycles through Default, Long Delay, and Timer Modes. Watch the MODE LED for off → blink → solid.
MANUAL Press and hold to advance the fleece motor. Use after maintenance to tighten the roll or check motor direction.
PAUSE
  • Press once → 30-minute pause (LED blinks).
  • Press twice → 12-hour pause (LED solid).
  • Press once while paused → Resume immediately.

Operating Modes

Default Mode

MODE LED: Off

Motor advances after the sensor stays submerged for about 30 seconds, then stops once it re-enters air.

Best for: Normal daily use when you prefer sensor-driven advances.
Long Delay Mode

MODE LED: Green (blinking)

Motor advances only after the sensor stays submerged for roughly 11 minutes, ignoring short pump-off events.

Best for: Systems where feeding pauses or maintenance often stop the return pump.
Timer Mode

MODE LED: Green (solid)

Timer Mode is experimental and runs the motor for 7.5 seconds every 12 hours regardless of sensor input. The actual amount of fleece advanced in each run depends on how much of the roll has already been used.

Important disclaimer: Timer Mode is an experimental feature provided for free. The actual amount of fleece advanced varies as the roll is used, and stability and performance are not guaranteed. This mode should only be used when sensor-based triggering is not possible, or when you have a special control requirement.

Best for: Rare situations where the sensor cannot reliably trigger an advance.

Recommendation: Sensor-triggered Default or Long Delay Modes remain the most efficient options. Only use Timer Mode when sensor triggering is not possible.

LED Indicators

LED State Meaning / Action
POWER On Controller has power and is ready.
Off No input power detected; verify the adapter connection.
MODE Off Meaning: Default Mode; sensor triggers a motor advance after ~30 seconds submerged.
Blinking Meaning: Long Delay Mode active.
Triggered by: Press MODE once from Default.
Reset: Press MODE again to return to Default.
Solid Meaning: Timer Mode is running an experimental 12-hour advance schedule, and the actual fleece length moved will vary as the roll wears down.
Triggered by: Press MODE twice from Default.
Reset: Press MODE again to cycle back to Default. Prefer Default or Long Delay whenever sensor triggering is possible.
ALARM Off System operating normally.
Blinking Meaning: Feeding pause.
Triggered by: Press PAUSE once.
Reset: Auto-resumes after 30 minutes or press PAUSE twice.
Solid Meaning: 12-hour maintenance pause.
Triggered by: Press PAUSE twice.
Reset: Auto-resumes after 12 hours or press PAUSE once to resume immediately.
Solid
and
beeping		 Meaning: Over-advancing alarm; the sensor stayed submerged too long.
Triggered by: Improper water level or sensor placement.
Reset: Adjust water level/sensor height, then press PAUSE once. Auto-resumes after 12 hours.

Additional Alerts

Motor or Circuit Fault

Alternating MODE and ALARM LEDs paired with rapid beeps indicate an electrical issue. Disconnect power and contact support.

Fleece Blockage or Depletion

Intermittent beeps with a blinking ALARM LED signal a clogged or empty roll. Replace the fleece and press PAUSE once.

No Controller Lights

If the controller does not power on, confirm the adapter connection or request a replacement from support.

Troubleshoot Steps

Use the guides below to resolve the most common issues.

Problem 1: Filter never advances

  • Make sure the filter is installed snugly, with not too much water bypassing the fleece.
  • Check the water blocker height. If a shorter/lower water blocker leaves a gap or allows too much bypass, use the taller water blocker.
  • For multi-sock sumps, check unused sock openings and covers so water cannot bypass around the rollers.
  • Lower the sensor a little at a time until the fleece advances.
  • Check the sump water level and adjust if needed.
  • If the chamber stays high while downstream water is low, check for restricted flow from dense media baskets or clogged downstream chambers.
  • Inspect and clean the sensor.

Problem 2: Rolls too frequently or triggers alarms

Work through these steps in order:

  1. Verify connections: Reconnect the sensor, motor, and controller plugs. Ensure connections are secure.
  2. Reset the sensor height: Move the sensor to the highest position.
  3. Run for 24 hours, then assess:
    • Case 1: Fleece is dark/dirty and the filter never rolled. Lower the sensor gradually until it just touches the water and triggers a roll. The water level should drop immediately—leave the sensor there. This is the optimal sensor position
      All set!
    • Case 2: The filter rolled and the used fleece is dirty (yellow to brown). Keep the sensor at the top; that is the optimal sensor position.
      All set!
    • Case 3: The filter rolled but the fleece is nearly clean or almost used up. Repeat these steps carefully. If it still over-rolls, contact support.
      Needs attention
  4. Contact support if needed:

Problem 3: Motor or controller loses power, flickers, or shuts off

Use this check if the controller lights dim, flicker, restart, or shut off when you press MANUAL or when the motor is connected.

  1. Stop running the motor repeatedly: Disconnect power before inspecting plugs or moving the filter.
  2. Reseat and dry the connections: Confirm the sensor, motor, controller, and power adapter plugs are fully seated. Keep the controller and power adapter dry.
  3. Check the motor load: If the controller stays on with the motor unplugged but flickers or shuts off when the motor is connected or manually advanced, the motor may have a short. This can happen if water gets into the motor. Do not keep testing under power; contact support with a short video of the behavior.
  4. Check the controller and power path: If the controller stays dark even with the motor unplugged, check the outlet, power adapter, and barrel connector. If it still does not power on, contact support for controller or power diagnosis.

FAQ

How does the automatic roller work?

The N-Clear M Filter uses an optical water-level sensor to detect when the fleece becomes clogged. As debris restricts flow, water rises inside the chamber until it reaches the sensor. The controller then advances fresh fleece, restoring flow and water clarity.

Which aquariums are compatible?

The filter fits most 4" filter sock sumps and many popular AIO systems. If you are unsure about compatibility, reach out to support@naturedimensions.com for guidance.

How should the sensor behave?

  • Default Mode: Advances after the sensor stays submerged for about 30 seconds.
  • Long Delay Mode: Advances after the sensor stays submerged for roughly 11 minutes.

After setup, the sensor should normally stay in one position. Raise it if the filter advances while the fleece still looks clean. Lower it only if dirty fleece has raised the water level but the filter is not advancing.

How often will the fleece advance?

Roll frequency varies by bioload, flow rate, and sensor height. It can advance every few hours or stretch beyond ten hours between cycles. Fleece rolls typically last 3-6 weeks. If a roll advances very quickly while the used fleece still looks clean, check water level, filter seating, bypass around the sock opening, and sensor position before replacing parts.

Why does my ATO react differently?

Expect slight water-level shifts between the display and rear chambers. Dirty fleece keeps more water in the display, while clean fleece lets more flow into the rear section. This behavior usually stabilizes within a day or two.

What comes with each filter?

Each N-Clear main filter includes the filter body, controller, optical sensor, motor, power adapter, and 1 starter fleece roll. A Main + Extension kit includes one starter roll per filter, but the extension shares the main controller and sensor; it does not include a separate controller, sensor, or power adapter. Sensor, motor, and power adapter cables are each about 150 cm / 60 in.

How does Main + Extension work?

The extension connects to the main controller. It does not include its own controller, sensor, or power adapter. All connected motors advance together when the main sensor triggers. If one roll stays much cleaner in a multi-sock sump, that opening may receive less flow; check for bypass or try placing the extension closer to the incoming water path.

What should I check for bypass around the N-Clear M?

Make sure the filter is seated snugly and the water blocker is high enough to direct water through the fleece. If the shorter/lower water blocker leaves a gap or allows too much bypass, use the taller water blocker. In multi-sock sumps, also check unused sock openings or covers because water can bypass through an open sock hole.

Why is one roll cleaner than the other?

In multi-sock sumps, one sock opening may naturally receive less flow than another. If one roll stays much cleaner, check for bypass through an unused opening or gap, then try placing the extension in the sock opening closest to the incoming water path.

How far can the controller be from the filter?

Sensor, motor, and power adapter cables are each about 150 cm / 60 in. Keep the controller within reach of both the sensor and motor connectors. The practical filter-to-outlet reach is about 300 cm / 120 in total: about 150 cm / 60 in from the filter to the controller, plus about 150 cm / 60 in from the controller to the power outlet. The Main + Extension splitter cable is for running two motor heads; it does not meaningfully extend the controller-to-filter distance.

Can I connect N-Clear to Hydros, Apex, or a 0-10V port?

N-Clear is designed to run through the included controller and sensor. Do not wire the motor directly to Hydros, Apex, or similar 0-10V control outputs. Those ports are usually low-current control signals, while the N-Clear motor needs 12 V power with enough startup current when it rolls. If you need scheduled operation, use the controller's Timer Mode only when sensor-based triggering is not possible.

What if the controller lights flicker or shut off when the motor runs?

Disconnect power and stop repeated testing. Reseat the plugs and make sure the controller and power adapter are dry. If the controller works until the motor is connected or MANUAL is pressed, the motor may have a short and should be diagnosed by support. If the controller stays dark even with the motor unplugged, check the outlet, power adapter, and barrel connector before contacting support.

What should I check if the filter is not rolling?

Confirm the filter is seated snugly and water is passing through the fleece. If the fleece is dirty and the water level has risen, lower the sensor one small step at a time until it triggers. If pressing Manual does not move the dirty roll, check the lower roll path for sand, shell, small rock, or other debris.

Safety Instructions

Read all instructions carefully before operating the N-Clear M Fleece Roller Filter. The device is for indoor use only, and the controller must not be exposed to water.

DANGER: To avoid electric shock, ensure the system is dry when connecting or disconnecting the power supply.

Important Safety Precautions

  • Do not use the device if the power cord, plug, or any component is damaged.
  • This product is suitable for users aged 14 and older, or younger users with supervision and guidance.
  • Keep the device out of reach of unsupervised children.
  • Only use the supplied power adapter.
  • Disconnect power before installation, removal, or cleaning.
  • Avoid pulling on the power cord when unplugging; grip the plug instead.

Technical Specifications

Supported Tanks

Fits most 30-120G tanks with minimum filter chamber clearance: 4" x 3.5" x 7" (102 mm x 90 mm x 180 mm)

  • 4" filter sock sump systems. No adapter needed.
  • 7" x 4.5" rectangular filter sock systems. N-Fit M adapter needed.
  • Innovative Marine 30/40/50. N-Fit M adapter needed.
  • Waterbox 65.4. N-Fit M adapter needed.
  • Tideline 31/47/62. N-Fit M adapter needed.

If your tank isn't on the list but has a filter sock opening larger than 4" x 3.5", feel free to reach out at support@naturedimensions.com. We're constantly expanding our adapter lineup to support more tank models.
Max Flow Rate 800 GPH (main), up to 1600 GPH (main + extension)
Dual Filter Support Yes - one controller supports two filters running in sync; ideal for dual filter chambers or dual filter socks.
Filter Dimensions Footprint: 4" x 3.5" (102 mm x 90 mm)
Height (excluding fleece): 15.75" (400 mm)
Minimum required clearance above the filter sock plate: 4" x 3.5" x 9.8" (102 mm x 90 mm x 250 mm)
Fleece Roll Dimensions Width: 2.4" (61 mm)
Length: 82 ft per roll
Fleece Roll Duration Fleece rolls typically last 3-6 weeks, depending on tank size, bioload, flow, and sensor height. Each N-Clear filter includes 1 starter fleece roll.
Operating Voltage 12V UL-certified power supply
Cable Lengths Sensor, motor, and power adapter cables are each about 150 cm / 60 in

Warranty

Product Warranty & Lifetime Support

Standard Warranty Coverage

We provide a one-year warranty covering the following N-Clear M components. Units purchased directly from Nature Dimensions receive an additional 6-month warranty extension, for 18 months of total coverage. Purchases through other retailers receive the standard 1-year warranty unless otherwise stated.

  • Feed shaft
  • Take-up shaft
  • Upper housing
  • Lower housing
  • Take-up motor
  • Sensor
  • Sensor bracket
  • Controller
  • Power adapter

Exclusions

The warranty does not cover damage resulting from:

  • Misuse, abuse, improper installation, or unauthorized modifications
  • Use of non-original or incompatible filter fleece rolls or accessories
  • Natural wear and tear or accidental damage
  • Repairs or servicing performed by anyone other than authorized service personnel
⚠ Fleece Roll WarningPlease do not use third-party fleece rolls. Differences in roll length, width, and thickness can place significantly different loads on the motor. Improper rolls can damage the motor and body, and any resulting damage will void the warranty.

How to File a Warranty Claim

Email support@naturedimensions.com with:

  • Proof of purchase (order confirmation or invoice)
  • A clear description of the issue
  • Photos or video evidence, if available

Note: Nature Dimensions LLC reserves the right to deny claims that do not meet the above criteria.

Customer Support

Need help with setup or troubleshooting? We aim to respond within 24 business hours. Reach us here:

Limitation of Liability

  • Nature Dimensions LLC is not liable for indirect, incidental, or consequential damages caused by the use or inability to use this product.
  • The warranty is valid only in the country of purchase unless otherwise required by law.

Lifetime Warranty via Auto-Refill Subscription

N-Clear Auto-Refill keeps your fleece rolls stocked automatically and extends your device warranty for as long as your subscription remains active and eligible.

Benefits:

  • Automatic delivery on your schedule.
  • Enjoy a 20% discount on every roll.
  • Lifetime device warranty with an active subscription.

Eligibility:

  • Subscription must remain active for at least three consecutive months.
  • Your device must continue to meet standard warranty conditions.

Subscribe now at naturedimensions.com/products/auto-refill-n-clear-m-fleece-roll-2-pack.

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