Introduction
This manual provides essential information for the proper installation, operation, and maintenance of your SYLVANIA T8 Gro-Lux Fluorescent Tube. SYLVANIA's GRO-LUX Aquarium fluorescent lamps are designed to provide the essential energy for use in indoor gardening applications. They deliver the right balance of red and blue wavelengths, which are most beneficial for chlorophyll synthesis, plant growth, and flowering processes. Photosynthetically Active Radiation (PAR) varies according to the specific plant cultivar being grown.
Safety Information
Please read and understand all safety instructions before installing or operating the fluorescent tube. Failure to do so may result in electric shock, fire, or other injuries.
- Always disconnect power to the fixture before installing, removing, or cleaning the lamp.
- Ensure the lamp is cool before handling.
- Do not use in wet locations unless the fixture is specifically rated for such use.
- Handle glass components with care to prevent breakage.
- Dispose of fluorescent lamps according to local regulations, as they may contain small amounts of mercury.
- This lamp is non-dimmable. Do not use with dimmer switches.
Setup and Installation
The SYLVANIA T8 Gro-Lux Fluorescent Tube is designed for easy installation into compatible T8 fluorescent fixtures with a G12 Bi-Pin base.
- Power Disconnection: Before beginning, ensure the power supply to the light fixture is completely turned off at the circuit breaker or wall switch.
- Remove Old Bulb (if applicable): If replacing an existing bulb, carefully twist the old fluorescent tube 90 degrees to align the pins with the slots in the lamp holders, then gently pull it out.
- Insert New Bulb: Align the two pins on each end of the SYLVANIA T8 Gro-Lux tube with the slots in the lamp holders of your fixture. Gently push the tube into the lamp holders until the pins are fully seated.
- Secure Bulb: Once the pins are seated, rotate the tube 90 degrees until it locks securely into place. The tube should feel firm and not wobble.
- Restore Power: Turn the power back on to the fixture. The lamp should illuminate immediately.

Figure 1: SYLVANIA T8 Gro-Lux Fluorescent Tube, ready for installation.

Figure 2: Detail of the G12 Bi-Pin base for proper fixture alignment.
Operating Instructions
The SYLVANIA T8 Gro-Lux Fluorescent Tube is specifically designed to support indoor gardening by providing the optimal light spectrum for plant photosynthesis and growth.
- Light Spectrum: This lamp emits a balanced spectrum of red and blue wavelengths, which are crucial for chlorophyll synthesis and enhancing vegetation.
- Photosynthetically Active Radiation (PAR): The light output is optimized for PAR, providing the necessary energy for all stages of indoor gardening, including germination, propagation, and mature plant growth.
- Usage: Simply turn on your compatible fluorescent fixture to activate the Gro-Lux lamp. The duration of light exposure should be adjusted based on the specific needs of your plants.

Figure 3: The Gro-Lux tube provides essential light for plant development.

Figure 4: Ideal for promoting growth and maintaining vegetation in various indoor setups.
Maintenance
The SYLVANIA T8 Gro-Lux Fluorescent Tube requires minimal maintenance to ensure optimal performance and longevity.
- Cleaning: Periodically, with the power off and the lamp cool, gently wipe the tube with a soft, dry cloth to remove any dust or debris that may accumulate and reduce light output. Do not use liquid cleaners directly on the bulb.
- Lamp Life: This fluorescent tube has an average rated life of 7,500 hours. Actual lifespan may vary depending on usage conditions, such as frequency of switching and ambient temperature.
- Replacement: Replace the lamp when it begins to flicker excessively, fails to light, or when its light output significantly diminishes.
Troubleshooting
If you experience issues with your SYLVANIA T8 Gro-Lux Fluorescent Tube, refer to the following common troubleshooting steps:
| Problem | Possible Cause | Solution |
|---|---|---|
| Lamp does not light up. | No power to the fixture, incorrect installation, faulty lamp, or faulty ballast/fixture. |
|
| Lamp flickers or cycles on and off. | Aging lamp, incorrect lamp type for fixture, or faulty ballast. |
|
| Reduced light output. | Dust accumulation, end of lamp life, or incorrect lamp for application. |
|
Specifications
Key technical specifications for the SYLVANIA T8 Gro-Lux Fluorescent Tube:
| Specification | Value |
|---|---|
| Model Number | 21657 |
| Light Type | Fluorescent |
| Bulb Shape Size | T8 |
| Wattage | 15 Watts |
| Bulb Base | G12 Bi-Pin |
| Brightness | 325 Lumens |
| Color Temperature | 5500 Kelvin |
| Voltage | 120 Volts |
| Average Life | 7500 Hours |
| Length | 18 inches |
| Product Dimensions (Approx.) | 1.16"W x 3"H (packaging) |
| Material | Glass |
| Indoor/Outdoor Usage | Indoor |

Figure 5: The SYLVANIA Gro-Lux tube is designed for optimal performance in indoor plant cultivation environments.
Warranty Information
This SYLVANIA T8 Gro-Lux Fluorescent Tube comes with a 2-year warranty from the date of purchase. This warranty covers defects in materials and workmanship under normal use. Please retain your proof of purchase for warranty claims. For full warranty terms and conditions, please refer to the official SYLVANIA website or contact customer support.
Customer Support
For technical assistance, product inquiries, or warranty claims, please contact SYLVANIA customer support through their official website or the contact information provided on the product packaging. When contacting support, please have your product model number (21657) and purchase date available.
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