ATO Systems & Reservoirs for Aquarium Plumbing

What does ATO stand for? An ATO is an Auto top off system.

Stop pouring water into your tank every day! Heat and water circulation cause aquarium evaporation. The most basic aquarium ATO is a float switch, which turns on a pump to replenish water lost to evaporation.

There are many advanced ATO systems, like the Auto Aqua Smart ATO or JBJ ATO, that use multiple water level sensors. When the water level drops, the ATO sensor turns on a pump sitting in an ATO reservoir. A good ATO will incorporate at least two sensors as a failsafe, so that a sensor failure doesn’t lead to an overflow. For example, the Tunze Osmolator (a best seller) has a mechanical float, an optical sensor, and an electronic failsafe. All of the sensors must fail for there to be a flood.

Use a kalkwasser reactor along with your ATO to raise pH and replenish calcium and alkalinity.
45 Results
XP Aqua Duetto ATO Auto Top Off System
17%
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XP Aqua Duetto ATO Auto Top Off System

Tunze Osmolator 3155 ATO Auto Top Off System
20%
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Tunze Osmolator 3155 ATO Auto Top Off System

Tunze Osmolator Nano 3152 ATO Auto Top Off System
15%
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Tunze Osmolator Nano 3152 ATO Auto Top Off System

Neptune Systems OS-1-M Optical Level Sensor with Magnetic Mount
10%
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Neptune Systems OS-1-M Optical Level Sensor with Magnetic Mount

Neptune ATK V2 Auto Top Off Kit
10%
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Neptune ATK V2 Auto Top Off Kit

Simplicity Dosing Container - 3 x 2L Compartments (6L Total)

Simplicity Dosing Container - 3 x 2L Compartments (6L Total)

Neptune Systems PMUP v2 Practical Multipurpose Utility Pump
10%
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Neptune Systems PMUP v2 Practical Multipurpose Utility Pump

Tunze Osmolator Replacement Metering Pump
15%
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Tunze Osmolator Replacement Metering Pump

Innovative Marine AUQA Gadget HydroFill Ti Auto Top Off ATO Reservoir - 5 Gallon
10%
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Innovative Marine AUQA Gadget HydroFill Ti Auto Top Off ATO Reservoir - 5 Gallon

Tunze Osmolator Storage Container 27L (7.1 Gal) ATO Reservoir
15%
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Tunze Osmolator Storage Container 27L (7.1 Gal) ATO Reservoir

IceCap Auto Top Off ATO
10%
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IceCap Auto Top Off ATO

Innovative Marine HydroFill Ti Auto Top Off ATO Controller
10%
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Innovative Marine HydroFill Ti Auto Top Off ATO Controller

JBJ ATO Automatic Top Off System Water Level Controller
15%
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JBJ ATO Automatic Top Off System Water Level Controller

JBJ Automatic Top Off Nano ATO with Pump
15%
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JBJ Automatic Top Off Nano ATO with Pump

Innovative Marine HydroFill Ti ATO Return Pump
10%
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Innovative Marine HydroFill Ti ATO Return Pump

Marine Depot Float Switch w/ Magnetic Mounting Bracket for Auto Top Off ATO
15%
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Marine Depot Float Switch w/ Magnetic Mounting Bracket for Auto Top Off ATO

Innovative Marine HydroFill Ti Universal Auto Top Off ATO Return Bracket
10%
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Innovative Marine HydroFill Ti Universal Auto Top Off ATO Return Bracket

Seachem Hydro Tote Collapsible Water Jug

Seachem Hydro Tote Collapsible Water Jug

XP Aqua Ultimate ATO - Complete 4-Sensor Aquarium Auto-Top-Off System
15%
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XP Aqua Ultimate ATO - Complete 4-Sensor Aquarium Auto-Top-Off System

Tunze Nano Osmolator Auto Top Off with 7.1 Gallon ATO Reservoir
15%
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Tunze Nano Osmolator Auto Top Off with 7.1 Gallon ATO Reservoir

Marine Depot Standard Float Switch for Auto Top Off ATO
15%
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Marine Depot Standard Float Switch for Auto Top Off ATO

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