Complete Guide to Coral Tank Lighting

Lighting selection is one of the most critical issues for successful coral tank keeping, alongside water quality management. Most corals obtain energy through photosynthesis performed by symbiotic zooxanthellae living within their bodies. Without adequate light, zooxanthellae decline, causing corals to bleach and weaken.

This article systematically explains the fundamental knowledge for selecting lighting for coral tanks, the characteristics of different lighting fixture types, how to consider light intensity and spectrum, and practical setup methods.

Basic Light Requirements for Corals

Light required by corals has two elements: "intensity (light quantity)" and "color (spectrum)."

Light Intensity (PAR Value): PAR (Photosynthetically Active Radiation) is an indicator of photosynthetically active radiation, and measured values from a PAR meter serve as a reference in coral keeping. General guidelines are as follows:

• Soft Corals: PAR 50–150
• LPS (Large Polyp Scleractinian Corals): PAR 100–250
• SPS (Small Polyp Scleractinian Corals): PAR 200–450 or higher

Even within the same tank, PAR values change significantly depending on the height at which corals are placed. Therefore, the convention is to position SPS corals that require high light intensity in the upper sections and soft corals that need low light intensity in the lower sections.

Spectrum (Light Color): Zooxanthellae in corals utilize blue light (around 400–490 nm) most efficiently for photosynthesis. Therefore, coral tank lighting emphasizes a spectrum centered on blue light. On the other hand, red and orange light tend to promote algae growth, so they are typically used sparingly in coral tanks.

In terms of aesthetic beauty, blue and cyan light bring out the fluorescent pigments in corals and create vivid coloration. Many enthusiasts prefer blue-toned lighting because it achieves both photosynthetic efficiency and visual beauty.

Types and Characteristics of Lighting Fixtures

Current coral tank lighting can be broadly divided into three types.

LED Lighting

This is the current mainstream and easy for beginners to use. It offers significant practical advantages: low power consumption, minimal heat generation, and a long lifespan (30,000–50,000 hours).

High-performance LEDs allow individual dimming of each color channel, enabling customization of the spectrum to your preference. Additionally, many products feature timer functions, sunrise and sunset simulations, and moonlight modes, making automation easy—another appealing aspect.

Representative products include Radion, AI Hydra, Kessil, Orphek, and EcoTech Marine, with prices ranging widely from tens of thousands to over 200,000 yen.

T5 Fluorescent Tubes

These are fluorescent tubes arranged in parallel and characterized by uniform light distribution. Unlike spotlighting from LEDs, they create few shadows and deliver light evenly throughout the tank.

Spectrum is adjusted by combining different tube types such as blue, white, and purple. Running costs are slightly higher than LED, and tube replacement is recommended every 12 months. Hybrid lights combining LED and T5 are also popular.

Metal Halide Lamps (Metal Halide)

Once the mainstream coral lighting, they are characterized by a spectrum close to natural sunlight and strong light intensity. The shimmering wave patterns on the water surface (glitter effect) are beautiful, and many enthusiasts still prefer this effect.

However, they consume significant power and generate considerable heat, often requiring a chiller for temperature management, resulting in high running costs. Today, as LED performance has improved, new installations are declining.

Key Points for Installing and Operating Lighting

Once you've purchased lighting, keep these operational points in mind.

Lighting Duration: Standard lighting duration for coral tanks is 8–10 hours per day. Too long can cause excessive algae blooms; too short can lead to insufficient energy for corals. Ideally, use a timer to turn lights on and off at the same time daily.

Light Acclimation: When introducing new corals or switching to new lighting, don't immediately run at full power. Instead, start at 30–50% output and gradually increase intensity over 2–4 weeks. Sudden changes in light intensity stress corals and can cause bleaching.

Regular Maintenance: Non-LED lighting requires periodic replacement. Even with LEDs, salt creep and dirt on the lens reduce light intensity, so clean regularly.

PAR Measurement: If possible, obtain a PAR meter and measure actual values at various points in the tank. This data helps optimize coral placement.

Recommended Setups by Budget

Here are recommended lighting setups by budget for beginners.

• Beginner Level (20,000–50,000 yen): Entry-level LED. Provides sufficient light intensity for soft coral and LPS care.
• Intermediate Level (50,000–150,000 yen): Multi-channel dimmable LED. Capable of handling SPS care with customizable spectrum.
• Advanced Level (150,000 yen and up): High-end LED or LED+T5 hybrid. Provides top-tier light environment for those pursuing enhanced SPS coloration.

You Can Also Consult About Coral Lighting at Bri-Choku

Since optimal coral lighting solutions depend on the product of "tank size × coral species being kept × installation environment," general information alone may not be sufficient for decision-making.

At Bri-Choku, you can purchase directly from specialist coral breeders and receive specific advice on optimal lighting conditions for your corals. Learning what types of lighting and settings the breeders actually use is a major advantage of direct sales. We invite you to find your ideal corals at Bri-Choku and create a beautiful reef tank.