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Auto Top Off Controller
Auto Top Off Controller

Please Note: Return of electrical equipment for exchange or store credit is limited to 30 days from the date of purchase. Beyond 30 days, please contact the manufacturer for repair or replacement as covered by the manufacturer's warranty.

Returned products must be unopened and in the original packaging to receive full store credit. Products that have been opened, used, or lightly used, will incur a 15% processing fee. Upon receipt of the returned product, store credit will be applied, minus the processing fee.

Rewards Program


*Automatically refills evaporated aquarium water
*Maintains aquarium and sump water level to prevent pump damage
*Save time and effort by automating aquarium top-offs

Automatically refill your sump or aquarium without lifting heavy buckets or spilling water. Floating sensors monitor water level and activate pump when water level drops due to evaporation. Helps maintain stable salinity/specific gravity and optimum water level to prevent pump from running dry. Features LED panel, Audible Signal alert and linkable brackets for installation. Requires water pump, sold separately.

Pump Safety Protection: The A.T.O. Controller automatically stops power to your top off pump in the event that your reservoir is low on water. The safety feature prevents pumps from running dry and failing.

Product Features
  • Automatically replenishes water to sump or tank due to evaporation.
  • Complete with Level Controller, (2) float sensors, and (2) mounting brackets.
  • Keeps pumps from running dry. Overflow protection (pump not included).
  • Visible LED indicators can be read day or night.
  • Audible alert signals when pump is in operation mode.

Usage Guide

  • Determine operation Mode (Mode A or Mode B).
  • Install Water Sensor 1 (#3) and Water Sensor 2 (#4) per diagram shown in Other Views of product.
  • Connect Water Sensor 1 and Water Sensor 2 into A.T.O. Level Controller.
  • Connect pump into A.T.O. Level Controller - Pump Power Output (#2).
  • Connect power cord to 115V AC outlet.
  • LED indicator will illuminate when power has been established.


  • Level Contoller MUST be installed in a well-ventilated dry surface.
  • A.T.O. Controller is NOT waterproof. Keep away from water contact. DO NOT operate A.T.O. Level Controller near magnets.


  • Please make sure that the output line from the pump/reservoir tank is NOT SUBMERSED in the sump. This will cause a back siphon and the water will flow back and forth constantly along with the audible alert.


  • Power Source - 115V AC, 60 Hz.
  • Purpose - Aquarium Automatic Water Level Controller.
  • Pump - Not Included.

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