Growing coral reefs in an aquarium requires meticulous attention to detail, replicating the natural conditions these delicate organisms need to thrive. Here's a breakdown of the key aspects:
1. Water Quality: The Foundation of a Healthy Reef
Maintaining pristine water quality is paramount. Corals are highly sensitive to changes in water chemistry.
- Salinity: Maintain a stable salinity level of 1.024-1.026 specific gravity.
- Temperature: Keep the water temperature stable between 72-78°F (22-26°C).
- pH: Aim for a pH level between 8.1 and 8.4.
- Alkalinity: Maintain alkalinity between 8-11 dKH (degrees of carbonate hardness). This buffers the pH.
- Calcium: Keep calcium levels between 400-450 ppm (parts per million).
- Magnesium: Maintain magnesium levels between 1250-1350 ppm.
- Nitrates and Phosphates: Keep these as close to zero as possible, as high levels can fuel algae growth, which can outcompete corals.
Regular water testing is essential to monitor these parameters and make necessary adjustments through water changes and supplementation. Invest in a reliable test kit or use a professional water testing service.
2. Lighting: Simulating the Sun
Corals rely on symbiotic algae called zooxanthellae that live within their tissues. These algae photosynthesize, providing the coral with nutrients. Therefore, proper lighting is crucial.
- Type of Lighting: Metal halide, LED, and T5 fluorescent lights are commonly used. LEDs are becoming increasingly popular due to their energy efficiency and controllability.
- Intensity and Spectrum: Different corals require different light intensities and spectrums. Soft corals generally need less light than small polyp stony (SPS) corals. Research the specific needs of the corals you plan to keep.
- Photoperiod: Maintain a consistent photoperiod of approximately 10-12 hours per day.
3. Water Flow: Delivering Nutrients and Removing Waste
Adequate water flow is essential for delivering nutrients to the corals and removing waste products.
- Flow Rate: The ideal flow rate depends on the type of coral, but generally, aim for a turnover rate of 20-50 times the tank volume per hour. SPS corals typically require higher flow rates.
- Type of Flow: Use powerheads or wavemakers to create turbulent, random flow patterns. This prevents dead spots and ensures all corals receive adequate circulation.
4. Nutrition: Supplementing Photosynthesis
While zooxanthellae provide most of the coral's nutritional needs, supplemental feeding can enhance growth and coloration.
- Types of Food: Coral foods come in various forms, including liquid, powder, and frozen. Select foods that are appropriately sized for the corals you are keeping.
- Feeding Schedule: Feed corals a few times a week. Overfeeding can lead to nutrient buildup and algae growth.
- Targeted Feeding: For some corals, especially larger polyp stony (LPS) corals, targeted feeding with a pipette can be beneficial.
5. Coral Placement and Aggression: Maintaining Harmony
Coral aggression is a critical factor to consider when stocking a reef aquarium.
- Spacing: Provide adequate space between corals to prevent them from stinging or shading each other.
- Aggression Levels: Research the aggression levels of different coral species before introducing them to the aquarium. Some corals release chemicals or have stinging tentacles that can harm or kill other corals.
- Placement Strategy: Place more aggressive corals upstream of less aggressive ones to minimize the impact of chemical warfare.
6. Substrate and Rockwork: Providing a Foundation
The substrate (sand or gravel) and rockwork provide a surface for beneficial bacteria to colonize and create a natural-looking environment.
- Live Rock: Live rock is rock that has been colonized by beneficial bacteria, algae, and other organisms. It plays a crucial role in biological filtration.
- Substrate Depth: A shallow sand bed (1-2 inches) is generally preferred to prevent the buildup of nitrates.
7. Quarantine: Preventing Disease Introduction
Before introducing any new corals to the main aquarium, quarantine them in a separate tank for several weeks. This allows you to observe them for signs of disease or pests and prevent the introduction of these problems to the established reef.
Table: Key Water Parameters for Reef Aquariums
| Parameter | Ideal Range |
|---|---|
| Salinity | 1.024-1.026 SG |
| Temperature | 72-78°F (22-26°C) |
| pH | 8.1-8.4 |
| Alkalinity | 8-11 dKH |
| Calcium | 400-450 ppm |
| Magnesium | 1250-1350 ppm |
| Nitrates | Close to 0 ppm |
| Phosphates | Close to 0 ppm |
By diligently maintaining these parameters and providing a stable, healthy environment, you can successfully grow coral reefs in your aquarium. Regular observation, testing, and adjustments are essential for long-term success.
