Choosing the right aquarium lighting is one of the most important decisions you’ll make as a fishkeeper. Not only does lighting bring out the colours of your aquascape, but it also supports plant growth, coral health, and the overall balance of your tank.
But the right setup isn’t the same for every aquarium. Freshwater and marine aquariums have very different lighting requirements, and selecting the wrong one could hold back your plants or corals. In this guide, we’ll break down the differences between freshwater and marine lighting, what you need to look for, and how to choose the right system for your aquarium.
Freshwater Aquarium Lighting
Spectrum Requirements
Freshwater aquariums, especially those with live plants, need full-spectrum lighting. This typically covers wavelengths between 400–700 nm, with strong emphasis on red and blue light for photosynthesis. A balance of green light ensures your fish and aquascape look natural.
Colour Temperature
Most planted aquariums thrive under 6,000–7,500K lighting — this mimics natural daylight and enhances plant growth. Warmer lights (3,000–5,000K) highlight reds and yellows, while cooler whites (>8,000K) give a crisper look but may not be ideal for plant growth.
PAR Levels
For freshwater aquaria:
- Low PAR (30–60): Good for easy plants (Anubias, Java fern).
- Medium PAR (60–120): Suitable for most stem plants and carpeting species.
- High PAR (120+): Needed for demanding aquascapes like Dutch or high-tech planted tanks with CO₂ injection.
Best Uses
- Planted aquascapes
- Fish-only freshwater tanks (where lighting is more for colour and aesthetics)
- Nano aquariums with compact LED setups
Product examples: Fluval Plant Spectrum LED
Marine Aquarium Lighting
Spectrum Requirements
Marine tanks, particularly reefs, rely heavily on the blue and violet spectrum (400–500 nm). These wavelengths fuel photosynthesis in the zooxanthellae algae that corals depend on for survival. Blue light also enhances coral fluorescence, making them appear vibrant under actinic lighting.
Colour Temperature
Marine lighting generally ranges from 10,000–20,000K. The higher Kelvin values provide the deep blue effect often associated with reef aquariums. This not only looks stunning but also supports coral growth at different depths.
PAR Levels
PAR intensity is critical in reef aquariums:
- Soft corals (80–150 PAR) – Moderate lighting needs.
- LPS corals (100–200 PAR) – Require stronger light for growth and colour.
- SPS corals (200–300+ PAR) – High-intensity light is essential, often needing premium LED systems.
Best Uses
- Coral reef aquariums (SPS, LPS, and soft corals)
- Marine fish-only setups with blue tint for aesthetics
- Large display tanks requiring controllable LED systems
Product examples: EcoTech Radion XR30w G6, AI Hydra 32HD.
Key Differences at a Glance
|
Feature |
Freshwater Lighting |
Marine Lighting |
|---|---|---|
|
Spectrum |
Full spectrum with red + blue peaks |
Blue/violet dominant |
|
Colour Temperature |
6,000–7,500K (natural daylight) |
10,000–20,000K (deep blue ocean) |
|
PAR Range |
30–120+ depending on plants |
80–300+ depending on corals |
|
Primary Purpose |
Plant growth + fish colour |
Coral health + fluorescence |
|
Aesthetic Look |
Bright, natural daylight |
Blue, glowing reef effect |
Other Factors to Consider
- Controllability: Marine LED systems often feature advanced app controls for sunrise/sunset simulation, lunar cycles, and spectrum adjustments. Freshwater lights may offer simpler programming focused on daylight cycles.
- Tank Depth: Deeper aquariums require higher-intensity lights, especially for marine reefs where corals demand strong PAR values.
- Energy Efficiency: Modern LEDs are the gold standard for both freshwater and marine tanks, offering high output with lower energy costs compared to T5 or halide systems.
Final Thoughts: Which Setup Do You Need?
The decision between freshwater and marine lighting depends entirely on your aquarium type:
- If you have a planted freshwater tank, go for a full-spectrum LED with 6,000–7,500K colour temperature and appropriate PAR for your plants.
- If you’re running a marine or reef tank, invest in a blue-heavy LED system with programmable controls and enough PAR intensity to support corals.
At Charterhouse Aquatics, we stock a full range of aquarium lighting solutions — from compact nano LEDs for freshwater tanks to high-power reef systems for demanding SPS corals. Whether you’re new to fishkeeping or building your dream reef, we can help you find the right lighting setup for your aquarium.
