Aquarium lighting

Lighting determines the growth of corals and plants. Too much light favours algae. Too little kills photosynthetic organisms.

Detailed explanation

The lighting has changed radically in the last 10 years. LEDs have almost completely replaced T5, HQI and T8 lamps. The advantages are enormous: reduced consumption, adjustable spectrum, duration 5-10 years.

For the reef the key parameter is PAR (Photosynthetically Active Radiation). SPS corals want 250-400 PAR. LPS are good at 100-200 PAR. Soft corals tolerate 50-150 PAR. Putting an SPS at 50 PAR means watching it slowly die. Putting a mushroom on 400 PAR means burning it.

The spectrum matters as much as the intensity. The reef corals appear more colourful with a blue cast (14,000-20,000 K). Aquatic plants grow best in warm white light (6,500-8,000K).

The photoperiod (hours of light per day) should not exceed 8-10 hours for reef and 6-8 hours for freshwater aquariums without CO2. With CO2 you can get to 10 hours.

For the ponds the lighting is natural (the sun). The problem is excess: too many hours of direct sun favour algae. Floating plants and water lilies help create shade.

Coralia Lab with the Light & Placement Optimizer (LPO) calculates the ideal PAR for each point of the aquarium and suggests where to position each coral based on its light needs.

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