Gravity-Fed Auto Top Off (ATO) Reservoir

Set It & Forget It: Reliable Gravity-Fed ATO

• Maintains Stable Water Levels Without Electronics
• Simple Gravity-Fed Design with No Floats or Switches to Fail
• Compact Over-Tank Reservoir for Aquariums up to 20 Gallons
• High-Quality Clear Acrylic with Easy Drip Feed Tube
• Works with Both Freshwater and Saltwater Aquariums

The Flipper Gravity-Fed Auto Top Off (ATO) Reservoir takes the hassle out of daily top-offs with a clean, straightforward design powered by gravity. Built from crystal-clear acrylic, this compact reservoir mounts directly over your aquarium with no electronics, pumps, floats, or valves to worry about. You get a safe and simple ATO system that just works.

Consistent water level means consistent salinity, which is critical for saltwater tanks. While ATO systems are most common for saltwater aquariums, freshwater setups can benefit too by eliminating the need for constant manual top offs.

How does it work?

The Flipper ATO works on the same principle as putting your finger over the top of a straw filled with water. Two feed tubes extend down into your aquarium: one slightly shorter than the other. When the water level drops below the shorter tube, air enters the reservoir and allows water to escape out of the longer tube. As the tank refills and the water rises to cover the shorter tube again, the flow stops automatically, just like lifting your finger from a straw. The result is a simple, reliable, and completely mechanical top-off system with no moving parts or electronics to fail.

Specifications

• Tank Size: Best for aquariums under 20 gallons (75 liters)
• Tank Length Compatibility: 16" to 20" (40 to 50 cm)
• Capacity: ~0.55 gallons (2.1 liters)
• Material: Clear acrylic
• Feed System: Gravity-fed drip tube
• Recommended Water: RODI or distilled

What's Included?

Flipper Gravity-Fed Auto Top Off Reservoir

2x Silicone Tubes

2x Metal Legs

Seal Plug