ATI® T5 HO Bulbs | The Industry Standard for Reef Lighting

Maintaining a high-performance reef requires a spectrum that balances coral health (photosynthesis) with aesthetic beauty (fluorescence). ATI® T5 bulbs are specifically designed to provide the precise wavelengths needed to drive coral growth while making every pigment in your aquarium pop.

Explore the ATI® Bulb Range

Bulb Name Spectrum/Kelvin Key Benefit
Blue Plus 460nm / 420nm The Best Seller: Maximizes PAR for SPS and fixes "yellow" hued tanks.
Coral Plus 15,000K+ Hybrid The Modern Hybrid: Blue Plus, Aquablue, and Purple Plus in one tube.
Aquablue Special 15,000K The Foundation: High PUR (Photosynthetically Usable Radiation) base bulb.
True Actinic 421nm Violet The Color Enhancer: Triggers deep fluorescent proteins for ultimate "glow."
Purple Plus Full Spectrum Warm The Aesthetic Booster: Brings out vivid reds, pinks, and purples.

Build Your Perfect Spectrum

ATI® bulbs are designed to be mixed and matched. By varying your bulb combinations, you can customize the visual look of your tank from a crisp 10K daylight to a deep 20K reef blue.

Popular 4-Bulb Combinations:

  • 12K–15K (Crisp White): 2 Blue Plus, 2 Aquablue Special.

  • 16K–20K (Ocean Blue): 3 Blue Plus, 1 Coral Plus (or Purple Plus).

  • The Hybrid Growth Mix: 2 Blue Plus, 1 Coral Plus, 1 Purple Plus.

Popular 6-Bulb Combinations:

  • The SPS Power Mix: 4 Blue Plus, 1 Coral Plus, 1 Purple Plus.

  • Deep Water Fluorescence: 4 Blue Plus, 2 True Actinic.

Frequently Asked Questions

How often should I replace my ATI® T5 bulbs?

For optimal performance and spectral stability, we recommend replacing bulbs every 9–12 months. While the bulb may still light up after this period, the spectrum shifts and the PAR output drops, which can lead to algae issues or poor coral growth.

Do I need to "season" new T5 bulbs?

Yes. For dimmable fixtures (like the ATI® SunPower Dimmable), it is critical to run new bulbs at 100% power for at least 50–100 hours before dimming them. This ensures the mercury is properly distributed and extends the bulb's lifespan.

Can I use T5 bulbs with my LED lights?

Absolutely. Many reefers use "Hybrid" lighting by adding T5 bulbs to their LED setup. The T5 bulbs provide a uniform "blanket" of light that fills in shadows created by LEDs, significantly reducing coral tissue loss on the undersides of large colonies.