Macroalgae

Macroalgae remain a cornerstone of marine aquarium management, used both for biological filtration in refugiums and as decorative "marine plants" in display tanks.

• Lighting: Requires moderate to high-intensity light in the 6,500K to 10,000K spectrum to thrive.
• Water Flow: Moderate flow is necessary to keep debris from settling in the algae and to ensure nutrient delivery.
• Pruning: Regular harvesting is mandatory. If allowed to overgrow, the bottom layers may die and rot, releasing stored nutrients back into the water.
• Chemical Balance: Macroalgae may compete with corals for nutrients. If levels drop too low (zero nitrates/phosphates), the algae may starve.

• Nutrient Export: As they grow, macroalgae consume nitrates and phosphates. Periodically harvesting (pruning) the algae physically removes these nutrients from the system.
• Natural Habitat: They provide a safe breeding ground for microfauna like copepods and amphipods, which serve as live food for delicate fish.
• pH Stabilization: Photosynthesis during the day increases oxygen and reduces CO2. Many hobbyists run refugium lights on a reverse cycle (lit at night) to prevent night-time pH drops.
• Food Source: Many species serve as supplemental nutrition for grazers like tangs, rabbitfish, and blennies