Tunze Osmolator 3 ATO - 3154

The Tunze Osmolator 3 ATO - 3154 is a premium automatic top-off system for freshwater and saltwater aquariums. It maintains a constant water level with a precise optical control sensor and an independent thermal safety sensor, helping reduce salinity swings in reef aquariums and keeping sump or aquarium water level more stable between manual refills.

Tunze Osmolator 3 ATO for Stable Aquarium Water Level

The Osmolator 3 is built as a plug-and-play top-off controller with fixed operating parameters based on Tunze's long-running Osmolator design experience. It includes the Turbelle High Jet 5030 dosing pump, magnetic sensor mounting, tube holder, hose, connector, and a 12 V DC power supply, so the system is ready to install with a separate freshwater reservoir.

Dual-Sensor ATO Safety and High Jet Pump Features

• Precise optical control sensor: Detects water level with 0.5 mm accuracy and is designed to resist air bubbles, deposits, and scratches.
• Independent thermal safety sensor: Stops the High Jet 5030 pump in an overfill condition for added overflow protection.
• Stable salinity support: Helps maintain consistent salt concentration in marine and reef aquariums by replacing evaporated freshwater automatically.
• High-head dosing pump: Includes the Turbelle High Jet 5030 pump with a maximum delivery height of 6.2 m or 20.34 ft.
• Integrated pump protection: High Jet 5030 includes dry-running and blockage protection for safer top-off operation.
• Plug-and-play setup: All required operating components are included except the freshwater reservoir.
• Compact mounting: Sensor holder works on glass up to 15 mm and the tube 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.
• Low-voltage operation: Uses a 12 V SELV power supply built to medical-technology standards.

Osmolator 3 3154 Specifications and Mounting Details

• Product type: Automatic top-off water level controller
• Tunze product number: 3154.000
• Use: Freshwater and saltwater aquarium top-off
• Control sensor: Optical level sensor with 0.5 mm accuracy
• Safety sensor: Independent thermal overfill safety sensor
• Included pump: Turbelle High Jet 5030 dosing pump
• Maximum pump head: 6.2 m or 20.34 ft
• Power supply: 100-240 V input with 12 V DC output
• Sensor glass thickness: Up to 15 mm or 0.59"
• Tube holder thickness: Up to 22 mm or 0.87"
• Reservoir: Not included

3154 ATO Installation and Aquarium Planning Notes

• Best application: Reef aquariums, saltwater systems, freshwater aquariums, sump systems, and display-edge installations that need dependable top-off control.
• Reef stability: Automatic freshwater replacement helps reduce salinity variation caused by evaporation.
• Reservoir placement: Use a clean freshwater reservoir sized appropriately for the aquarium's evaporation rate.
• Back-siphon prevention: Position the outlet line so it cannot siphon reservoir water into the aquarium after the pump stops.
• Maintenance access: Install sensors where they can be inspected and cleaned without dismantling the aquarium setup.

Tunze Osmolator 3 Setup Directions

1. Choose a mounting location in the sump, rear chamber, or aquarium edge where the water level should remain constant.
2. Mount the optical control sensor and independent thermal safety sensor on clean glass within the supported thickness range.
3. Place the freshwater reservoir below or beside the aquarium system as appropriate for the installation.
4. Install the Turbelle High Jet 5030 pump in the reservoir and route the supplied hose to the aquarium or sump.
5. Secure the tube holder so the outlet cannot move, fall out, or create a siphon.
6. Connect the controller and 12 V power supply according to the Tunze instructions.
7. Test the system through several top-off cycles before relying on it unattended.
8. Inspect the sensor area, pump intake, hose, and reservoir level regularly.

What's Included

• Tunze Osmolator 3 ATO - 3154
• Optical level sensor with magnet holder
• Independent thermal safety sensor
• Turbelle High Jet 5030 dosing pump
• 12 V DC power supply
• PU hose
• Push-in fitting
• Tube holder