Shopping Cart

Your cart is empty

Continue Shopping

Hygger [ HG987 ]

Hygger Mini Auto Top Off Aquarium Water Refiller Kit

Free Shipping & Return On All Orders!  Free Shipping & Return On All Orders!
  • Smart ATO water pump
  • Small and compact design
  • Sound alarm
  • Led indicators alarm
  • Auto refill and one-key drain water
  • Easy to install and use

Hygger Mini Auto Top Off Aquarium Water Refiller Kit


  • Description
  • Specification & Package
  • Instructions
  • FAQ

Dual Optical Sensor Monitors

Hygger aquarium water filler comes with 2 monitors.

ATO Monitor

The ATO monitor is used to keep track of the water line in the tank. When the water level drops to a certain level, the water pump will be activated to fill water to the tank. The internal part and the external part of the ATO monitor mounted together by magnetism. To ensure strong mounting, the tank thickness should be less than 1/2 inch.

External Monitor

The external sensor monitor is used to monitor the external reservoir’s water level. It ensures the water pump not running in dry reservoir. You can install the external sensors on the reservoir wall or in the reservoir if the reservoir tank wall is too thick. The cable coming with the external sensor monitor is 5.1 feet long.

Products info
Products info

Overfill Protection

Except the sensor used to sense the low water level where water pump is activated to refill water, there is another sensor built in the ATO monitor that is designed to sense the high water level where the water pump automatically shuts off to stop refilling water. Thereby, it effectively prevents over filling.

Different Indicators Mean Different Working States

There are 4 indicator lights on the ATO (auto top off) monitor.

Yellow light on means it is draining water; Yellow light flashing means the water pump is running in dry condition or the water pump is damaged.

Blue light on means it is refilling water; Blue light flashing means the water pump is running in dry condition or the water pump is damaged.

Green light on means the reservoir’s water level is being monitored. Green light flashing means there is water shortage of the reservoir. You need to add water to the external reservoir.

Red light is the power indicator. If it is flashing, please check if the power adapter is damaged.

Products info
Products info

Double-Function Water Pump

The water pump can be used to drain water from the tank, and refill water to the tank. You can long press M button to switch between drainage mode and water refilling mode.

To drain water, you need to install the water pump in the bottom of the tank, and plug the power adapter to the drainage jack near the yellow indicator.

To refill water, you need to install the water pump in the external reservoir / bucket, and plug the power adapter to the water refilling jack near the blue indicator.

5.9 Feet Long Hose with Hose Holder

The water hose can be mounted on the tank with hose holder. The holder can be installed on rimmed or rimless aquariums up to 3/4 inch. Make sure the water hose is installed above the water level to prevent siphon when the pump shuts off. Also, keep it away from the ATO internal monitor.

Products info
Products info

Suitable for Transparent Tank Wall

Since the monitors are built with optical sensors, they only work for tanks with transparent wall. Tanks with opaque wall is not suitable for this water refiller tool. As long as the tank wall is transparent, no matter it is reef aquarium, saltwater aquarium, or freshwater aquarium, the water refiller will be working.

 Warnings and Warm Tips

1. The ATO monitor should be placed higher than the water level.

2. Place the water hose somewhere away from the ATO internal monitor.

3. Ripples will affect the performance of ATO internal monitor. Please avoid ripples. Otherwise, the ATO monitor is incapable of sensing water level.

4. Please always keep the ATO internal sensor clean. Otherwise, the sensor will lose its sensitivity.

5. ATO external monitor is not waterproof.

6. ATO monitor should be placed at the level where you want to refill water.

 Product Parameters

Water Refiller

Model Applicable Tank Size Water Pipe Length External Sensor Cable Length
HG-987 Up to 60 Gallons 5.9 Feet 5.1 Feet

Water Pump

Voltage Head Max Max Flow Rate Cable Length Max Lift
DC 12 V 6.5 Feet 74 GPH 6 Feet 4.9 Feet

 Packing List

  • ATO Monitor x1
  • External Sensor x1
  • DC Water Pump x1
  • 12 V DC Power Adapter x1
  • 5.9 Feet Water Pipe x1
  • Pipe Holder x1
  • User Manual x1
Hygger Mini Auto Top Off Aquarium Water Refiller Kit
Usre Manual
Question:How do you mount this unit if your aquarium has trim along the top of the tank? it is to think with the trim.
Answer:  If the guard is blocking it you would have to mount it under the plastics guard if it was a rimless tank you would have no issues and I would assume you would need it to be attached to each other with something clear and not have something plastic or anything that would block the signal from the mount to the main controller.
By Gary S. on July 8, 2021
Question:Will the sensor works in darkness? My sump is under my stand with no light. Will it still work?
Answer:  Yes, it can work in darkness. Only need to ensure that the sensor is installed on the transparent tank wall.
By usmagob SELLER on July 30, 2021
Question:Can the alarm be silenced?
Answer:  The alarm will not be muted. If an alarm occurs, the situation is abnormal, which needs to be manually checked to correct the problem.
If it is an overflow alarm, it will stop working automatically, but you need to manually adjust the position of the ATO, the alarm will be released.
By usmagob SELLER on June 30, 2021
Question:Having an issue where it keeps filling into sump even though it has stopped the pump.
Answer:  Make sure the end of the output hose is higher than the reservoir water level.
By Ron Leva on January 4, 2022