FZONE Aquarium ATO Auto Top Off System with Dual Optical Sensors (Green)

Effortless, precise top-offs for reef and freshwater tanks

Meet the FZONE Aquarium ATO, a compact auto top-off system designed to keep water levels stable without taking up valuable space. With a footprint as slim as 0.7 inches, it fits neatly in tight spots and can be mounted in rimed or rimless tanks or sumps. Dual precision optical sensors monitor the water surface in real time, helping to minimize fluctuations and maintain a steady environment for your aquatic display.

Advanced safety and reliability you can count on

Powered by a trio of innovative technologies—EFTT (Extended-Filling-Time Technology), AFT (Anti-fluctuation Technology), and QST 2.0 (Quick-Security Technology)—this ATO is built for dependable operation. EFTT assesses tank size to estimate how long filling should take, while QST 2.0 provides real-time alerts and stops refilling to prevent overfill. AFT helps avoid unnecessary pump activation by continually measuring water level and adjusting behavior accordingly. Real-time protection and smart safeguards are designed to keep your reef or freshwater setup safer, without promising outcomes that can’t be guaranteed.

• Dual optical sensors deliver continuous water-level data and keep fluctuations under 0.6 cm.
• QST 2.0 alerts you if refilling takes unusually long or a sensor/controller issue is detected.
• EFTT estimates fill time based on tank size to reduce guesswork during top-offs.
• AFT minimizes pump activity when a refill isn’t needed, helping conserve energy and reduce wear.
• Included check valve prevents backflow, preserving display water clarity and salinity stability.

Powerful, compact, and easy to install

The unit includes a 74 GPH pump capable of lifting water up to 2 meters, enabling reliable top-offs even for larger aquariums. The magnetic mounting system supports tank walls up to 20 mm (0.78 inches) thick, offering strong, flexible placement options. All essential accessories are included in the package, so setup is straightforward right out of the box.

• Small form factor makes placement in tight spaces simple.
• Magnetic mounting and a robust check valve contribute to a tidy, safer installation.
• Suitable for both reef-ready and standard freshwater tanks with minimal configuration.

Around-the-clock support and ongoing improvements

FZONE backs the ATO with a responsive customer service team ready to assist you with product-related questions or setup guidance. Continuous improvements and thoughtful design focus on making top-offs smoother and more reliable for your ongoing aquarist journey.