Tunze Osmolator Nano 3 ATO - 3151

The Tunze Osmolator Nano 3 ATO - 3151 is a compact automatic top-off system for smaller aquarium systems up to approximately 250 litres or 66 US gallons. It uses a single precise optical water-level sensor, selectable maximum dosing duration, a quiet 12 V dosing pump, hose, holder, magnet mount, and sensor protection cover for simple freshwater top-off control in nano and small aquarium setups.

Tunze Osmolator Nano 3 for Compact ATO Control

The Osmolator Nano 3 is built for aquariums that need reliable automatic top-off in a smaller and simpler format than the full Osmolator 3. It can be installed in cabinet filter systems, rear chambers, or directly on the aquarium edge, making it a practical choice for nano reef tanks, small marine aquariums, and freshwater systems where evaporation causes water-level changes.

Single-Sensor Nano ATO Features

• Designed for smaller systems: Suitable for aquarium systems up to approximately 250 L or 66 US gallons.
• Precise optical sensor: Detects water level with 0.5 mm accuracy and is designed to resist air bubbles, deposits, and scratches.
• Simple one-sensor setup: Uses a compact single-sensor design for straightforward nano aquarium installation.
• Selectable dosing limit: Two maximum dosing-duration settings allow the amount of top-off water to be matched to aquarium size.
• Quiet High Jet pump: Includes the Turbelle High Jet 5030 with dry-running and blockage protection.
• Nano-friendly mounting: Sensor mount works on glass up to 12 mm and the hose holder works on edges up to 22 mm.
• German-made hose: Includes flexible PU hose that is low-emission, hydrolysis-resistant, microbe-resistant, and resistant to kinking when routed properly.
• Protective sensor cover: Helps shield the sensor during regular aquarium use.

Osmolator Nano 3 3151 Specifications

• Product type: Compact automatic top-off water level controller
• Tunze product number: 3151.000
• Recommended aquarium size: Up to approximately 250 L or 66 US gallons
• Control sensor: Single optical water-level sensor
• Sensor accuracy: 0.5 mm
• Included pump: Turbelle High Jet 5030 low-voltage dosing pump
• Maximum pump head: 3 m or 9.8 ft
• Power supply: 12 V DC
• Sensor glass thickness: Up to 12 mm or 1/2"
• Tube holder thickness: Up to 22 mm or 0.87"
• Included hose length: 3 m
• Reservoir: Not included

3151 Nano Aquarium Fit and Safety Notes

• Best application: Nano aquariums, small reef tanks, compact all-in-one aquariums, and small freshwater systems.
• Salinity stability: Helps reduce salinity swings in smaller marine aquariums where evaporation has a faster effect.
• Single-sensor planning: Use the selectable dosing-duration limit carefully and match it to the aquarium size and reservoir volume.
• Outlet positioning: Route the top-off outlet so it cannot back-siphon or slip below the aquarium waterline.
• Reservoir sizing: Use a clean freshwater reservoir that is appropriate for the aquarium and does not create excessive risk if misconfigured.

Tunze Osmolator Nano 3 Setup Directions

1. Install the optical sensor in the aquarium, rear chamber, or filter compartment at the desired operating water level.
2. Use the magnet holder on clean glass within the supported 12 mm thickness range.
3. Place the low-voltage dosing pump in a clean freshwater reservoir.
4. Route the 3 m hose from the reservoir to the aquarium or filter chamber and secure it with the hose holder.
5. Set the appropriate maximum dosing-duration level for the aquarium size.
6. Test the top-off function before leaving the system unattended.
7. Inspect the sensor, pump, hose, and reservoir regularly during routine maintenance.

What's Included

• Tunze Osmolator Nano 3 ATO - 3151
• Optical sensor with magnet holder
• Protective cover for sensor
• Low-voltage dosing pump
• 12 V power supply
• 3 m hose
• Hose holder