The AutoAqua ATO Duo G2

The AutoAqua ATO Duo is a smart and compact automatic top-off system designed to keep water levels stable in marine aquariums. Evaporation causes salinity to rise over time, and the ATO Duo solves this by automatically replacing evaporated water with fresh RO/DI water.
Unlike traditional float-based systems, the ATO Duo uses two optical sensors — one for primary water-level detection and a second as a backup safety sensor. This dual-sensor design eliminates moving parts, reducing the risk of failure due to salt creep, debris, or mechanical wear.
The integrated controller is built directly into the sensor housing, making installation fast and clutter-free. When the water level drops, the system activates the included pump to restore the correct level automatically. An LED indicator and audible alarm provide instant feedback and alert you to any abnormal conditions.

Designed for reliability and ease of use, the AutoAqua ATO Duo is an essential piece of equipment for marine fish keepers who want stable salinity, reduced daily maintenance, and peace of mind.

Specifications
Product Type: Automatic top-off system
Application: Marine fish tanks
Sensor Type: Dual optical water-level sensors
Safety Features: Backup optical sensor and audible alarm
Pump Type: DC submersible pump
Maximum Pump Flow Rate: ± 280 l per hour
Maximum Pump Head Height: ± 280 cm
Tubing Size: 6 mm
Power Input: 100–240 V AC, 50–60 Hz
Output Power: 12 V DC
Power Consumption: ≤ 5 W
Mounting Method: Magnetic mount
Recommended Glass Thickness: Up to 12 mm
Suitable Tank Size: Nano to medium marine aquariums