Adding Coral in Aquarium: A Saltwater Coral Reef Guide

Creating a coral reef aquarium is the next step to a saltwater tank. Bringing the colorful coral reef into your home requires careful planning and attention to detail. I’m going to walk you through the three main areas that you need to know to start growing corals.

I’ve been growing coral for over 10+ years and I can’t get enough of it. I’m always trying to find new colors, try new species, and even frag my own pieces. The best quote I got from a local fish store is:

If you can see rock, you got room for coral

Getting Started with Coral in Aquariums

Coral is a marine invertebrate that forms colonies made up of individual polyps. These polyps secrete calcium carbonate, creating the hard skeleton that we commonly recognize as coral. They are related to the jellyfish and sea anemones.

Corals are often classified into two main types:

• Hard Coral: Includes species like Acropora and Montipora, known for their rigid skeletons.
• Soft Coral: Includes species like Zoanthids and Mushroom Corals, which are more flexible and do not have a hard skeleton.

Why Keep Coral in Aquariums?

Corals enhance the beauty of an aquarium by adding vibrant colors and dynamic structures. They create a more natural environment for marine life, offering shelter and food sources for saltwater fish and invertebrates. As you observe the growth and changes, it can be quite rewarding.

Benefits of Coral in Aquariums

While there are many mental and health benefits of an aquarium, nothing is better than looking at a full tank of coral.

• Aesthetic Appeal: Corals provide a diverse range of colors and shapes, making your aquarium visually stunning.
• Ecosystem Support: Corals help maintain a balanced ecosystem within the tank by providing habitat and contributing to the biological filtration process.
• Educational Value: Keeping coral can teach you about marine biology, water chemistry, and the delicate balance required to maintain an aquarium.

Types of Corals Suitable for Beginners

For beginner aquarists, soft corals like zoanthids and polyps are recommended as they are more tolerant of fluctuations in water parameters. These corals are easier to care for and can thrive in a reef tank with minimal care. With proper care, coral can live over ten years in an aquarium.

Soft Corals

• Mushroom Corals (Actinodiscus): Easy to care for, tolerant of different lighting conditions.
• Zoanthid (Zoanthus): Vibrant colors, easy to propagate.
• Leather Corals (Sarcophyton): Require moderate light and water flow, resilient to changes.

Large Polyp Stony (LPS) Corals

• Hammer Coral (Euphyllia ancora): Unique hammer-shaped polyps, moderate lighting.
• Frogspawn Coral (Euphyllia divisa): Similar care to hammer corals, adds movement to the tank.
• Candy Cane Coral (Caulastrea): Easy to feed and maintain, bright colors.

Small Polp SPS Corals

• Bird’s Nest Coral (Seriatopora): Requires strong light and moderate flow, but is relatively easy to care for.
• Montipora: Available in various forms like plating or encrusting, requires stable conditions.

Essential Equipment for Coral Aquariums

Setting up a coral aquarium requires specific equipment such as a filtration system, lighting, and water flow. Maintaining stable water chemistry is the most important task. Meaning that you need to keep your calcium, alkalinity, and magnesium stable at all times.

Water Flow

Proper water circulation is necessary for coral health, aiding in nutrient distribution and waste removal. Use powerheads or wave makers to create consistent flow patterns, ensuring all corals receive adequate water movement.

Lighting

Corals require specific lighting to survive and grow. High-quality LED lights are more popular than T5 fluorescent bulbs, mainly for their energy efficiency and customizable spectrum options. The light should replicate natural sunlight, supporting coral photosynthesis.

• Intensity: Adjust based on coral type (e.g., higher for SPS corals).
• Spectrum: Ensure full-spectrum lighting, including blue and UV light.

Filtration System

A filtration system is critical for maintaining water quality.

• Protein Skimmer: Removes organic waste before it breaks down.
• Biological Filtration: Live rock or bio-media to support beneficial bacteria.

Water Testing Kits

Regularly monitoring water parameters is essential. Test kits should cover:

Parameter	Recommended Range
pH	8.1 – 8.4
Ammonia	0 ppm (should always be undetectable)
Nitrite	0 ppm (should always be undetectable)
Nitrate	0 – 10 ppm (lower is better, but avoid 0 ppm as some corals need minimal nitrate)
Calcium	400 – 450 ppm
Alkalinity	8 – 12 dKH (142 – 214 ppm)
Magnesium	1250 – 1350 ppm

Acclimating Coral to the Aquarium Water

Acclimating coral to your aquarium is a crucial process that can significantly impact the health and survival of your coral. Proper acclimation minimizes stress, helps the coral adjust to the new environment, and increases the chances of survival.

Here’s a step-by-step guide on how to acclimate coral.

1. Float the Coral Bag

Floating the coral bag in your aquarium helps equalize the temperature between the water in the bag and the aquarium water. This is an important step to prevent temperature shock, which can be harmful to the coral.

• Equalize Temperature: Place the sealed bag containing the coral in your aquarium, allowing it to float on the surface.
• Duration: Let the bag float for 15-30 minutes. This time allows the temperature inside the bag to gradually match that of the aquarium water.

Temperature acclimation is a crucial step, don’t skip it.

2. Start Drip Acclimation

Once the temperature has equalized, it’s time to begin the drip acclimation process. This method slowly introduces the coral to the aquarium water, helping it adjust to any differences in water chemistry.

• Transfer Coral to Container: After floating the bag, open it and carefully pour the coral and water into a clean container.
• Set Up Drip Acclimation: Use airline tubing to start a siphon from the aquarium to the container. Adjust the drip rate to about 2-4 drips per second using a clamp or by tying a knot in the tubing.
• Gradual Mixing: Let the aquarium water slowly drip into the container, gradually mixing with the coral’s original water. This allows the coral to adjust slowly to the new water chemistry.
• Duration: Continue the drip acclimation process for 20 mins. Every 20 mins test the salinity of the water in the container with the water from your tank, once the salinity matches. You’re good to go.

Drip acclimation is the most recommended way as it slowly introduces the coral to the new environment.

3. Place The Coral In The Tank

After the acclimation process is complete, it’s time to carefully transfer the coral to your aquarium. This step requires careful handling to avoid damaging the coral.

• Minimize Air Exposure: Carefully lift the coral from the container and submerge it into the aquarium water. Avoid exposing the coral to air for too long, as this can cause stress or damage.
• Positioning: Place the coral in its designated spot in the tank, ensuring it has adequate lighting and water flow based on its species’ needs.
• Secure Placement: Make sure the coral is securely positioned to prevent it from being dislodged by water currents or tank inhabitants.

I like to put my corals on the bottom of the tank for about 1-2 weeks to get them used to the lighting before placing them in a permanate location.

Maintaining and Growing Coral in Aquariums

Maintaining and growing coral in aquariums requires a balance of knowledge, dedication, and attention to detail. Corals are living organisms with specific needs, and understanding these needs is essential for creating a reef environment. This section will guide you through essential practices, feeding routines, disease prevention, troubleshooting common issues, and advanced methods to help you nurture a vibrant coral aquarium. 

Enhancing Coral Color and Growth

Achieving vibrant coral color and optimal growth requires a combination of proper lighting, stable water chemistry, and balanced nutrition. Ensure your lighting system provides the full spectrum, especially blue and UV light, which enhances coral fluorescence.

Maintaining calcium, alkalinity, and magnesium within recommended ranges supports healthy skeletal growth. Regularly dose trace elements, such as iodine, iron, and strontium, to boost color intensity.

Only dose elements that you have a test kit for.

Feed corals with a variety of foods, including amino acids and fatty acids, to provide the necessary nutrients for pigmentation and growth. Optimize water flow to ensure all corals receive adequate circulation, which aids in nutrient uptake and waste removal.

Regular Maintenance Practices

Regular maintenance is crucial for a coral aquarium. Begin by conducting weekly water tests to monitor parameters such as pH, calcium, alkalinity, and magnesium.

• You should be already performing your weekly 10% water change to remove accumulated toxins and replenish essential minerals.
• Clean the protein skimmer regularly to ensure efficient waste removal.
• Replace filter media, such as activated carbon, monthly to keep the water clear and free of contaminants.
• Keep an eye on water flow equipment, cleaning powerheads and pumps to prevent clogging and ensure consistent circulation.

Feeding Your Coral: What and How Often?

Corals obtain nutrition from both photosynthesis and direct feeding. While light provides energy via symbiotic zooxanthellae, many corals also benefit from supplemental feeding. Feed corals with reef-specific foods, including phytoplankton, zooplankton, and specialized coral foods like amino acids and liquid coral feeds.

I personaly don’t directly feed my corals but I have seen people have great results in doing so.

Overfeeding can lead to poor water quality, so feed sparingly and observe coral response to adjust feeding schedules.

Common Coral Diseases and How to Treat Them

Coral diseases can impact the health of your reef tank, so early detection and treatment are key.

The only one I have come across in my 10+ years is Coral Bleaching. Which is the easiest to prevent by researching the conditions your coral species require.

Some common coral diseases are:

• Coral Bleaching: Caused by stress factors like high temperatures, resulting in loss of color. Lower tank temperature and provide stable water conditions to aid recovery. Maintain stable water parameters and quarantine new corals to prevent disease introduction.
• Black Band Disease: A bacterial infection that appears as a dark band moving across the coral, leaving dead tissue behind. Treatment involves removing the infected area and improving water quality. Increased water flow and reduce nutrient levels can help prevent its spread.
• Yellow Band Disease: A disease that causes a yellow band of dead tissue to form on coral, primarily affecting stony corals like Acropora. Treatment includes removing the affected areas and improving water quality. Regular monitoring and maintaining stable conditions are crucial for prevention.
• White Band Disease: Affects stony corals, characterized by tissue loss. Isolate affected corals and improve water quality. There is no specific cure, so prevention through quarantine and stable tank conditions is essential.
• Dark Spot Disease: A condition where corals develop dark spots or patches, often due to stress or physical damage. Treatment includes improving water quality and reducing stressors like aggressive tank mates or unstable water parameters. Ensure adequate light and water flow to promote recovery.

Troubleshooting Common Coral Problems

Monitoring and maintaining coral health is the fun part of having corals in your aquarium. When corals exhibit signs of stress or poor health, identifying and addressing the underlying issues promptly is essential. 

Coral Issue	Possible Cause	Recommended Action
Closed Coral Polyps	Elevated nitrates, unstable parameters	Check water quality, and adjust parameters as needed
Color Loss in Corals	Insufficient light, poor water flow (food)	Ensure appropriate lighting, adjust water circulation
Algae Growth on Corals	Excess nutrients	Reduce feeding, increase water changes, clean the tank
Receding or Tissue-Losing Corals	Pests (e.g., flatworms, nudibranchs)	Inspect for pests, apply appropriate treatments
General Stress Signs	Various (e.g., water quality, pests)	Regular observation, test all water parameters

Frequently Asked Questions

What are the best corals for beginners?

For beginner aquarists, it is recommended to start with soft corals like zoanthids and polyps. These types are more tolerant of fluctuations in water parameters.

How do I know if my coral is healthy?

To determine if your coral is healthy, watch for signs of vibrant coloration, extended polyps, and active tentacle movement. Healthy corals will show growth and expansion in the right conditions. Regularly monitoring water parameters such as alkalinity, calcium, and magnesium levels is crucial for maintaining a coral reef aquarium.

What are the signs of coral bleaching?

Signs of coral bleaching include a loss of color, pale or white appearance, and retracted polyps. Coral bleaching occurs when corals are stressed by factors like high temperatures or changes in water chemistry. Proper monitoring of water conditions can help prevent the effects of coral bleaching.

Is it OK to put coral in a fish tank?

Yes, it is suitable to put coral in a fish tank, especially in a well-maintained saltwater aquarium. Corals not only enhance the aesthetics of the tank but also contribute to the overall health of the ecosystem. Proper acclimation, water quality management, and suitable tank mates are essential factors to consider when introducing coral to a fish tank.

When to add corals to reef tank?

It is crucial to add coral to your aquarium once the tank is fully cycled, and stable water parameters are maintained. Acclimating the coral gradually to match the tank’s salinity, temperature, and lighting conditions is essential for a smooth transition. Adding coral too soon can lead to stress and potential health issues for the coral inhabitants.