Lighting is one of the most important factors in maintaining a successful reef aquarium. While water chemistry, flow, and nutrient management all play crucial roles, corals ultimately rely on light to power photosynthesis and fuel growth. Red Sea’s ReefLED range was designed specifically with coral health in mind, providing a reef-safe spectrum that simplifies lighting decisions while delivering impressive colour and growth.
However, to get the most from your ReefLED fixture, it’s important to understand PAR levels, spectrum settings, and correct mounting heights. Proper setup can make the difference between thriving corals and disappointing results.
In this guide, we’ll explain how Red Sea ReefLED lighting works and help you optimise your setup for healthy coral growth and vibrant colouration.
What Makes Red Sea ReefLED Different?
Unlike many aquarium lights that offer dozens of colour channels and endless adjustment options, the ReefLED was designed around a simpler philosophy.
Red Sea engineered the fixture to provide:
- Reef-safe spectrum
- Strong blue-light output
- Optimal coral fluorescence
- Simple user control
- Consistent PAR distribution
Rather than allowing users to create potentially harmful lighting combinations, ReefLED focuses on delivering proven coral-friendly light profiles.
Popular models include:
- ReefLED 50
- ReefLED 90
- ReefLED 160S
Each model follows the same core lighting principles.
Understanding PAR
PAR stands for:
Photosynthetically Active Radiation
It measures the amount of usable light available to photosynthetic organisms such as corals and zooxanthellae.
Unlike wattage, PAR provides a much more meaningful indication of lighting performance.
Why PAR Matters
Corals use PAR to:
- Drive photosynthesis
- Produce energy
- Support growth
- Maintain colouration
Too little PAR can result in:
- Slow growth
- Browning corals
- Poor polyp extension
Too much PAR can cause:
- Bleaching
- Tissue recession
- Coral stress
Finding the right balance is essential.
Recommended PAR Levels for Corals
Different coral species require different light intensities.
Soft Corals
Examples:
- Zoanthids
- Mushrooms
- Leather corals
Recommended PAR:
50–150
LPS Corals
Examples:
- Euphyllia
- Acanthastrea
- Blastomussa
Recommended PAR:
75–200
SPS Corals
Examples:
- Acropora
- Montipora
- Stylophora
Recommended PAR:
200–400+
Many successful SPS aquariums maintain PAR levels between 250 and 350 throughout much of the upper reef structure.
ReefLED Coverage and PAR Performance
ReefLED 50
Best suited for:
- Nano reefs
- Small mixed reefs
- Soft coral aquariums
Coverage area:
Approximately 50cm x 50cm
ReefLED 90
The most popular model in the range.
Suitable for:
- Mixed reefs
- SPS/LPS systems
- Medium-sized aquariums
Coverage area:
Approximately 60cm x 60cm
ReefLED 160S
Designed for:
- Larger reef aquariums
- SPS-dominated systems
- Wide aquascapes
Coverage area:
Approximately 75cm x 75cm
Actual PAR will vary depending on mounting height and aquarium depth.
Understanding the ReefLED Spectrum
One of the biggest advantages of ReefLED fixtures is their carefully engineered spectrum.
Reef-Spec Blue Channel
The primary light source is the Reef-Spec Blue channel.
This combines wavelengths that support:
- Coral growth
- Photosynthesis
- Fluorescence
These wavelengths closely match the light corals receive on natural reefs.
White Channel
The white channel enhances:
- Visual appearance
- Natural colour rendering
- Daytime viewing
It is designed to complement the blue spectrum without reducing coral performance.
Moonlight Channel
The dedicated moonlight system provides:
- Night-time viewing
- Lunar simulation
- Reduced fish stress
Moonlight should remain subtle rather than bright.
Recommended Spectrum Settings
For most reef aquariums, Red Sea’s default presets perform exceptionally well.
Mixed Reef
A balanced approach suitable for:
- SPS
- LPS
- Soft corals
Typical settings:
- Reef-Spec Blue: 100%
- White: 15–25%
SPS-Dominated Systems
Focus on growth and colour.
Typical settings:
- Reef-Spec Blue: 100%
- White: 5–15%
LPS and Soft Coral Systems
Can tolerate slightly higher white levels.
Typical settings:
- Reef-Spec Blue: 100%
- White: 20–30%
The blue channel should remain the dominant source of illumination.
Mounting Height Guidelines
Mounting height significantly affects both PAR and coverage.
Mount Too Low
Potential problems:
- Hotspots
- Uneven spread
- Shadowing
Mount Too High
Potential problems:
- Reduced PAR
- Excessive light spill
- Lower efficiency
Recommended Mounting Heights
ReefLED 50
20–25cm above water surface
ReefLED 90
20–30cm above water surface
ReefLED 160S
25–35cm above water surface
These heights typically provide the best balance of intensity and coverage.
Choosing the Right Mounting System
Red Sea offers several mounting solutions.
Tank Mount Arm
Ideal for:
- Rimless aquariums
- Clean appearance
- Easy adjustment
Suspension Kit
Suitable for:
- Open-top displays
- Multiple fixtures
- Contemporary installations
Custom Mounting Rails
Useful for larger systems using multiple ReefLED units.
Choose a mounting method that allows easy height adjustment.
Optimising Coverage
Coverage is often just as important as intensity.
Avoid Shadowing
Large rock structures can block light.
Position corals carefully and consider fixture placement when aquascaping.
Use Multiple Fixtures for Larger Tanks
Rather than relying on a single powerful fixture, multiple units often provide:
- Better spread
- Reduced shadowing
- More even PAR distribution
This is particularly important in SPS-dominated aquariums.
Acclimating Corals to ReefLED Lighting
One of the most common mistakes reef keepers make is introducing corals to full intensity immediately.
Why Acclimation Matters
Corals require time to adjust to changes in light intensity.
Without acclimation:
- Bleaching may occur
- Polyp extension may decrease
- Growth can slow temporarily
Using ReefBeat Acclimation Mode
ReefBeat includes a built-in acclimation feature.
This gradually increases intensity over a chosen period.
Recommended acclimation duration:
Existing Reef Upgrade
2–4 weeks
New Corals
2–6 weeks
SPS Introductions
4–6 weeks
Gradual increases are always safer than rapid changes.
Recommended Photoperiod
Most reef aquariums benefit from:
Total Lighting Period
10–12 hours
Peak Intensity
8–10 hours
Sunrise and Sunset
1–2 hour ramps
The ReefBeat app makes programming these schedules straightforward.
PAR Mapping Your Aquarium
For the most accurate results, consider using a PAR meter.
PAR mapping allows you to:
- Identify hotspots
- Locate low-light zones
- Place corals appropriately
Many advanced reef keepers create dedicated PAR maps before finalising coral placement.
Common ReefLED Setup Mistakes
Running White Too High
Excessive white light can:
- Encourage algae
- Reduce fluorescence
- Increase glare
Mounting Too Low
Can create uneven PAR distribution.
Skipping Acclimation
One of the leading causes of coral bleaching after lighting upgrades.
Constantly Adjusting Settings
Corals prefer stability.
Frequent changes often create more problems than they solve.
Example ReefLED Layouts
60cm Mixed Reef
- One ReefLED 90
90cm Mixed Reef
- Two ReefLED 90s
120cm SPS Reef
- Two or three ReefLED 160S fixtures
150cm SPS Reef
- Three or four ReefLED 160S fixtures
Actual requirements vary depending on aquascape design and coral placement.
Final Thoughts
The Red Sea ReefLED range simplifies reef lighting by providing a proven coral-friendly spectrum that prioritises growth, colouration, and ease of use. By understanding PAR requirements, using appropriate mounting heights, and taking advantage of ReefBeat’s acclimation features, reef keepers can achieve excellent results with minimal guesswork.
Whether you’re running a nano reef filled with soft corals or a large SPS-dominated display, proper placement and programming of your ReefLED fixtures will help create a healthier, more vibrant reef aquarium.
At Charterhouse Aquatics, we stock the complete Red Sea ReefLED range, mounting arms, suspension kits, ReefBeat-compatible equipment, PAR meters, and reef aquarium accessories to help you build the perfect lighting system.
