The JBJ ATO water level controller is an advanced auto top off device that safely delivers freshwater into your aquarium to replenish water that is lost due to evaporation.

The unit utilizes two float sensors to detect water level that are held in place with adjustable brackets to accommodate various level requirements. Each sensor comes with a protective shield to prevent the interference from snails, crabs and other obstructions.

The intelligent controller has a US standard 3 prong receptacle that will accept any pump or powerhead with a maximum energy draw of 2 amps. The audible alarm can be switched on or off and will notify you of a failure. It also has a built in maximum pump operating time which can be adjusted up to a maximum of 14 minutes. This feature prevents the fill pump from running any longer than the specified period which helps prevent accidental over fill.

The unique feature of the JBJ ATO unit is the two different modes of operation; Mode A is designed to utilize one float sensor in your sump or aquarium and the second sensor is placed in your ATO reservoir to prevent your fill pump from running dry.

Mode B utilizes both sensors in your sump or aquarium to detect water level. This is great for small tanks or small return pump chambers where the water level fluctuates frequently. The high and low sensors will prevent the ATO from constantly turning on and off because of small variations in the water level.

If your looking for a safe and easy way to top off your aquarium, be sure to check out the JBJ ATO system at

Until next time, take care and happy reefkeeping!



JBJ ATO Automatic Top Off System Water Level Controller

JBJ Automatic Top Off System With Acella Powerhead/Pump