The TUNZE® Osmolator® 3 and Osmolator® 3 nano are compact, plug & play automatic top-off systems designed to maintain stable water levels in freshwater and marine aquariums. Both models ensure precise, safe operation with key differences in capacity and sensor design to suit varying aquarium sizes.

The Osmolator® 3 is ideal for larger tanks and includes a dual-sensor system—a high-precision optical sensor and an independent thermal safety sensor. This configuration offers 0.5 mm water level accuracy and full overflow protection. It includes the high-performance Turbelle® High Jet 5030 dosing pump with dry-run and blockage protection, capable of a delivery height up to 6.2 m. The system supports glass thickness up to 15 mm and comes with a kink-resistant PU hose, 12V DC medical-grade power supply, and push-in hose connector.

The Osmolator® 3 nano is tailored for aquariums up to 250 litres. It uses a single optical sensor for 0.5 mm accuracy and includes the same reliable Turbelle® High Jet 5030 pump with 3 m delivery height. It’s quick to install and includes a 12V power supply, 3 m hose, magnet holder (up to 12 mm glass), and sensor protection cover.

Key Features:

• Accurate auto top-off systems for fresh and saltwater aquariums
• Osmolator® 3: Dual sensors (optical + thermal safety)
• Osmolator® 3 nano: Single optical sensor (up to 250L tanks)
• 0.5 mm sensor accuracy – unaffected by bubbles or debris
• Quiet, efficient Turbelle® High Jet 5030 dosing pump included
• Plug & play setup – no software configuration required
• Kink-resistant PU hose with push-in connector (standard on Osmolator® 3)
• Mounting options for glass up to 15 mm (Osmolator® 3) or 12 mm (Nano)
• Tube holder compatible with rims up to 22 mm
• Made in Germany with 5-year warranty

Whether you're maintaining a compact reef tank or a larger marine system, the Osmolator® 3 range provides dependable, precise top-off control to keep salinity stable and water levels consistent—without the hassle of manual refills.

Specifications:

• For aquariums up to 250 litres
• Sensor accuracy: ±0.5 mm
• Glass compatibility: up to 12 mm
• Pump delivery height: up to 3 m
• Includes: 12V power supply, 3 m hose, magnet holder, sensor cover

• For freshwater and seawater systems
• Sensor accuracy: ±0.5 mm
• Glass compatibility: up to 15 mm
• Pump delivery height: up to 6.2 m
• Includes: 12V SELV power supply, PU hose, hose connector, dual sensors

Aquacadabra acts as credit broker/intermediary and not as a lender.

Klarna's credit products are provided by Klarna Bank AB, which is authorised and regulated by the Swedish Financial Services Authority, with limited supervision by the Financial Conduct Authority. More information can be found here.

Newpay finance options are provided through Deko’s platform by NewDay. P.D. Aquatics Ltd, t/a Aquacadabra is an Introducer Appointed Representative of Pay4Later Ltd, t/a Deko, which is authorised and regulated by the Financial Conduct Authority (ref no 728646) and is a credit broker, not a lender. NewDay Ltd is authorised and regulated by the Financial Conduct Authority (ref no 690292) and is authorised by the Financial Conduct Authority under the Payment Services Regulations 2017 for the provision of payment services (ref no 555318). More information can be found by clicking the newpay option above, or in the Newpay FAQs.

We really want you to be happy with the product that you've received. If however, when the goods arrive they're not what you want, then no problem - we have a 60 day no quibble return guarantee. Just let us know that you're going to return the item(s) by contacting us(stating your Order Number) and complete the returns packing slip that will have been included with your delivery. This will help us to quickly identify the item that you have returned (unopened and unused) - and we'll put a refund through for you.