1. Introduction
This manual provides detailed instructions for the installation, operation, and maintenance of your hygger Auto On Off LED Aquarium Light, model HG-999. This full-spectrum LED light is designed for freshwater planted tanks, offering a 24/7 lighting cycle with adjustable timer, multiple color options, and IP68 waterproof rating.
The light features WRGB lamp beads scientifically adjusted to simulate natural light, promoting plant growth and enhancing the visual vibrancy of your aquarium. Its optimized design ensures good waterproof performance and efficient heat dissipation.

Image 1.1: hygger Auto On Off LED Aquarium Light with its wired controller.
2. Safety Instructions
- Ensure the power supply voltage matches the product's requirements.
- Do not operate the light if the cord or plug is damaged.
- Always unplug the light before performing any maintenance or cleaning.
- The light unit is IP68 waterproof, but the power adapter and controller are not. Keep them away from water.
- Do not attempt to disassemble or modify the light unit.
- Keep out of reach of children.
3. Package Contents
Verify that all items are present in the package:
- 1 x LED light with wired controller
- 1 x AC/DC power adapter
- 2 x Adjustable metal brackets
- 1 x User manual (this document)
4. Setup
Follow these steps to set up your aquarium light:
- Attach Brackets: Slide the adjustable metal brackets onto both ends of the LED light fixture.
- Position Light: Place the light fixture on top of your aquarium, adjusting the brackets to fit the tank's width (suitable for 30-36 inch tanks). Ensure the light is centered and stable.
- Connect Power: Connect the wired controller to the LED light fixture, then plug the AC/DC power adapter into the controller. Finally, plug the power adapter into a suitable electrical outlet.

Image 4.1: The adjustable metal brackets allow for flexible tank fitting.
5. Operating Instructions
The hygger aquarium light features a wired controller with an LCD monitor for easy programming. The controller has six setting buttons:
- Up/Down Arrows: Adjust values (time, brightness, color).
- M (Mode) Button: Cycles through programming modes (51, 52, 53) and confirms settings.
- Light Bulb Button: Manually turns the light on/off or adjusts brightness in manual mode.
- Color Wheel Button: Cycles through different colors in manual mode.
- Gear Button: Used for setting the current time.

Image 5.1: The wired controller with LCD monitor and control buttons.
5.1. Setting Current Time
- After plugging in the light, the LCD monitor will display the current time.
- Press and hold the Gear Button for 3 seconds until the hour digit flashes.
- Use the Up/Down Arrows to adjust the hour. Press the Gear Button to confirm and move to minutes.
- Use the Up/Down Arrows to adjust the minutes. Press the Gear Button to confirm.
- The current time is now set.
5.2. Programming Auto Modes (Daylight & Moonlight)
This mode provides a preset 24/7 lighting cycle simulating sunrise, daylight, sunset, and moonlight.
- Daylight Mode (Mode 51):
- Press the M (Mode) Button once until '51' appears on the screen.
- Press and hold the M Button for 3 seconds until 'DAY-L ON' flashes.
- Use Up/Down Arrows to set the desired daylight ON time (e.g., 8:00). Press M Button to confirm.
- Set the desired daylight OFF time (e.g., 18:00). Press M Button to confirm.
- Adjust the white light brightness (10%-100%). Press M Button to confirm.
- Moonlight Mode (Mode 52):
- Press the M (Mode) Button again until '52' appears on the screen.
- Press and hold the M Button for 3 seconds until 'MOON-L ON' flashes.
- Use Up/Down Arrows to set the desired moonlight ON time (e.g., 18:00). Press M Button to confirm.
- Set the desired moonlight OFF time (e.g., 22:00). Press M Button to confirm.
- Select one of the 7 available colors (Red, Orange, Yellow, Green, Cyan, Blue, Purple). Press M Button to confirm.
- Adjust the brightness (10%-100%). Press M Button to confirm.

Image 5.2: Day Mode cycle with gradual intensity changes.

Image 5.3: Night Mode cycle with various color options.
5.3. Programming DIY Mode (Mode 53)
The DIY mode allows for custom programming of 8 time periods over 24 hours, with free combination of start time, end time, light color, and brightness.
- Press the M (Mode) Button until '53' appears on the screen.
- Press and hold the M Button for 3 seconds until 'ON' or 'OFF' flashes for the first time period (L1).
- Use Up/Down Arrows to select 'ON' or 'OFF' for the light. Press M Button to confirm.
- If 'ON' is selected, set the ON time (hour and minute) using Up/Down Arrows and confirming with M Button.
- Set the OFF time (hour and minute) using Up/Down Arrows and confirming with M Button.
- Adjust the brightness percentage (0-100%) for White (W), Red (R), Green (G), and Blue (B) LEDs individually. Use Up/Down Arrows to change values and M Button to cycle through W, R, G, B and confirm each.
- Repeat steps 2-6 for all 8 time periods (L1 to L8).

Image 5.4: DIY Mode allows for custom 24-hour light programming.
5.4. Manual Operation
To manually control the light:
- Press the Light Bulb Button to turn the light on or off.
- When the light is on, press the Light Bulb Button repeatedly to cycle through brightness levels (10% increments).
- Press the Color Wheel Button to cycle through different colors (white, red, green, blue, and combinations).
5.5. Video Tutorial: Programming Hygger 24/7 Light
Video 5.1: A detailed tutorial on programming the Hygger 24/7 LED Aquarium Light, including setting time and various modes.
6. Maintenance
Regular maintenance ensures optimal performance and longevity of your aquarium light:
- Cleaning: Gently wipe the LED light surface with a soft, damp cloth to remove dust or water spots. Do not use abrasive cleaners or solvents.
- Power Off: Always unplug the light from the power source before cleaning or performing any maintenance.
- Inspection: Periodically check the power cord and connections for any signs of damage. If damage is found, discontinue use and contact customer support.
7. Troubleshooting
If you encounter issues with your hygger aquarium light, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Light does not turn on. | No power, loose connection, or faulty adapter. | Check power outlet, ensure all connections are secure. Test with another outlet. |
| Timer settings are incorrect or light turns on/off at wrong times. | Current time not set correctly, or auto mode/DIY mode not programmed properly. Power outage may reset clock. | Re-set the current time (Section 5.1). Re-program the desired operating mode (Section 5.2 or 5.3). |
| Light flickers or changes color unexpectedly. | Loose connection, water ingress into controller, or internal fault. | Check connections. Ensure controller is dry. If problem persists, contact customer support. |
| Brightness cannot be adjusted. | Operating in a mode that does not allow brightness adjustment (e.g., certain moonlight settings). | Switch to a mode that allows brightness adjustment (e.g., manual mode or DIY mode). |
8. Specifications
| Feature | Specification |
|---|---|
| Model | HG-999 |
| Wattage | 26 Watts |
| Voltage | 20 Volts |
| Amperage | 0.6 Amps |
| Brightness | Greater than 1720 Lumen |
| Color Temperature | 6800 Kelvin |
| Color Rendering Index (CRI) | 89 |
| Light Source Type | LED (WRGB) |
| Waterproof Rating | IP68 |
| Material | Aluminum |
| Product Dimensions | 15.43 x 4.84 x 2.4 inches (Light fixture only) |
| Adjustable Tank Size | 30-36 inches |

Image 8.1: Detailed dimensions of the light fixture and power components.
9. Warranty and Support
For warranty information or technical support, please refer to the contact details provided on the product packaging or visit the official hygger website. Keep your purchase receipt for warranty claims.





