How do I choose the right corals for my reef tank? Expert Tips and Considerations

How do I choose the right corals for my reef tank? Expert Tips and Considerations


Choosing the right corals for a reef tank can be an exciting and sometimes challenging task. There are so many beautiful corals to choose from, each offering its unique colors and textures. To choose suitable corals for your reef tank, it’s essential to understand their individual needs for water quality, light, water flow, and food. 

Compatibility with other tank inhabitants is critical when choosing corals for your reef tank. It’s crucial to ensure that the chosen corals can coexist harmoniously with the fish and other invertebrates sharing the same environment. Researching and seeking guidance from experts or fellow aquarists is invaluable when creating a thriving and cohesive reef tank ecosystem.

Being mindful of coral growth patterns is another essential factor in choosing suitable corals. Familiarizing yourself with how corals can grow and spread in an aquarium will help avoid overcrowding and ensure that each coral has enough space to thrive. Careful planning and placement of corals within the tank will result in a visually appealing and well-balanced reef aquarium.

Understanding Coral Types

When it comes to selecting suitable corals for your reef tank, it’s essential to understand the different coral types. Corals are generally categorized into three main groups: Hard Corals, Soft Corals, and Polyps. Each category presents unique characteristics, care requirements, and appearances. Gaining an understanding of these varieties will help you make a more informed decision for your reef tank.

Hard Corals

Hard corals, also known as stony corals or Scleractinia, are the most common corals found in reef tanks. They have a hard calcium carbonate skeleton, supporting the coral’s polyps. Hard corals are typically slow-growing and require good water quality, intense light, and proper water movement. Some popular complex coral species include Acropora, Montipora, and Brain corals. These corals often serve as the foundation for reef tanks, providing a stable structure for other coral species to grow.

Acropora Coral
Acropora Vermiculata

Soft Corals

Soft corals are more flexible and do not have a hard calcium carbonate skeleton like hard corals. Instead, they generally have a smoother, more pliable texture and often sway with the water’s movement. Soft corals are considered easier to care for than hard corals, as they are more forgiving of variations in water quality, lighting, and flow. Some popular soft coral species include Leather Corals, Mushroom Corals, and Green Star Polyps.


Polyps are small, individual coral animals that can grow individually or as part of a larger colony. There are two main types of polyps: Large Polyp Stony (LPS) and Small Polyp Stony (SPS). LPS corals are generally more prominent, with more substantial polyps, and are typically easier to care for than SPS corals. SPS corals, on the other hand, have small polyps and often require more care and attention, making them more suitable for experienced reef tank hobbyists. Some popular LPS species include Euphyllia, Favia, and Goniopora, while popular SPS species are Acropora, Montipora, and Stylophora.

By learning about the different coral types, you can decide which corals will be best suited for your reef tank. Consider factors such as care requirements, compatibility with other coral species, and the intended aesthetic of your reef tank before making your final selections.

Analyzing Your Reef Tank

Before choosing the suitable corals for your reef tank, you must analyze your aquarium’s specific conditions. This ensures that the corals you select will thrive in your tank’s environment, some key factors to consider are tank size, lighting, water flow, and water parameters.

Tank Size

Tank size plays a significant role in determining which corals are suitable for your aquarium. Larger tanks offer more stability in water parameters and allow for a wider variety of coral species. Smaller tanks, on the other hand, may limit your options to more hardy and low-maintenance corals. Additionally, it’s crucial to consider spacing between corals to prevent aggressive interactions or overcrowding.


Lighting is essential for coral growth, as most corals contain symbiotic algae that require light for photosynthesis. When choosing corals, it’s essential to match their lighting requirements with the capabilities of your aquarium’s lighting system. Common categories of coral lighting needs include low, moderate, and high light, so it’s crucial to understand the output of your lighting equipment.

Some popular coral species and their lighting requirements:

Soft corals: low to moderate light

LPS (Large Polyp Stony) corals: moderate light

SPS (Small Polyp Stony) corals: high light

Water Flow

Water flow is another essential factor for coral health, as it helps in nutrient delivery and waste removal while simulating a natural environment. Corals have different water flow requirements, so it’s important to provide adequate water movement in your aquarium. You may need to adjust your pump or circulation equipment to accommodate these needs.

Examples of coral preferences in terms of water flow:

Soft corals: low to moderate flow

LPS corals: moderate flow

SPS corals: high flow

Water Parameters

Stable and suitable water parameters are critical for coral growth and overall health. You must monitor and maintain parameters such as temperature, salinity, pH, alkalinity, calcium, and magnesium. Consistency is key – sudden fluctuations can lead to coral stress and even death.

Ideal water parameters for most reef tanks:

Parameter Ideal Range

Temperature 75-79°F (24-26°C)

Salinity 1.023-1.025 s.g.

pH 8.0-8.3

Alkalinity 8-12 dKH

Calcium 350-450 ppm

Magnesium 1200-1350 ppm

Compatibility Factors

When choosing the right corals for your reef tank, it’s crucial to consider compatibility factors so that all the organisms coexist harmoniously. This section will cover coral compatibility and fish compatibility.

Coral Compatibility

Before adding new corals to your reef tank, research their compatibility with the existing corals to avoid unwanted interactions that can lead to coral stress or death. Take into account factors like:

Aggression: Certain corals can be aggressive, releasing toxins or using their tentacles to sting other corals. Ensure that aggressive species are placed far enough away from others to prevent harm.

Space requirements: Each coral species may have different growth patterns and space requirements. Plan your reef tank layout accordingly to provide adequate room for growth and prevent overcrowding.

Light and flow preferences: Different corals require varying light and water flow levels for optimal health. Position corals with similar preferences together to maintain a balanced environment for all inhabitants.

Fish Compatibility

When creating a vibrant coral reef aquarium, choosing the right fish as tank mates is crucial for maintaining a harmonious and balanced ecosystem. Fortunately, there are several species that can coexist peacefully in a coral reef environment. One of the most popular choices is the clownfish, known for its striking colors and iconic symbiotic relationship with anemones. These small, territorial fish are generally peaceful and make an excellent addition to any reef tank.

2 Clownfish swimming around coral
Clownfish make great tank mates for coral

Another compatible option is the royal gramma, a stunningly beautiful fish that adds a pop of vibrant purple and yellow to the tank. They are generally peaceful and get along well with other reef inhabitants. Additionally, the firefish, with its slender body and striking patterns, is an excellent choice for a peaceful community tank. These are just a few examples of the many fish species that can thrive alongside corals in a well-maintained coral reef aquarium. Remember to research the specific requirements and behaviors of each species to ensure compatibility and provide a safe and suitable environment for all tank inhabitants.

  • Research fish species that are known to coexist well with corals, refraining from adding those that can damage or eat corals.
  • Keep a balanced fish population to avoid excessive competition for resources, which can lead to territorial aggression and coral distress.
  • Monitor behavior to ensure a healthy and non-disruptive environment for both fish and corals.

By thoroughly investigating compatibility factors prior to introducing new corals and fish into your reef tank, you can create a thriving and harmonious aquatic ecosystem.

Coral Placement

Picking the perfect corals for your aquarium involves not only selecting the suitable species but also paying close attention to coral placement. In this section, we will discuss the importance of space requirements and ideal locations for different types of corals in your tank.

Space Requirements

Ensuring adequate space for each coral is vital for maintaining their health and promoting growth. Corals need ample room to expand without competing with their neighbors for light, nutrients, and space. Ideally, corals should be placed with sufficient gaps between them so that their growth won’t lead to overcrowding or aggressive interactions between species.

Using a PAR meter to measure the light levels in your tank can help you place corals in the right location based on their lighting requirements. This ensures that each coral receives an adequate amount of light for their growth and overall health.

Ideal Locations

Corals have varying lighting, water flow, and substrate preferences, which dictate their ideal placement within the tank. Understanding coral preferences can help you create a thriving ecosystem that caters to the needs of each species.

High-light corals: Some corals, such as SPS corals, require intense lighting to thrive. These should be placed higher up in the tank to maximize their exposure to light. However, ensure they are placed low enough that they don’t breach the surface as they grow (World Wide Corals).

Low-light corals: LPS and soft corals are less sensitive to light and water flow. They tend to prefer lower-flow, partially shaded areas, making them ideal residents for the lower or middle sections of the tank (World Wide Corals).

Substrate preference: Corals also differ in their preferred substrate types. For instance, some soft corals prefer sand, while others attach to rocks. Ensure that the coral’s preferred substrate is available in their designated area.

Keep in mind that coral placement is not set in stone. Make adjustments as needed to account for growth and the specific needs of your tank’s inhabitants. Regular monitoring and maintenance of your reef tank will ensure a healthy and thriving coral community.

Coral Care and Growth

When choosing the right corals for your reef tank, understanding their care and growth requirements is crucial to maintaining a healthy and thriving aquatic environment.

Feeding Requirements

Corals have different feeding requirements, depending on their species. Some corals obtain nutrients mainly from the photosynthesis of their symbiotic algae (zooxanthellae), while others require additional feeding, such as plankton, in order to thrive.

It is vital to research the specific nutritional needs of the corals you select for your reef tank to ensure their long-term health and growth.

For instance, certain corals, like mushroom corals and leather corals, are low-maintenance and do not require supplemental feeding. In contrast, large polyp stony (LPS) corals and some soft corals may benefit from additional planktonic feedings.

Growth Rates

Corals exhibit varying growth rates, which can affect your reef tank’s overall appearance and dynamic. Gaining knowledge of the growth patterns of each coral species is essential to ensure that they do not outcompete other corals for space or resources.

For beginners, consider choosing slower-growing corals, such as mushroom corals, zoanthids, and star polyps, as they are more forgiving and require less maintenance.

On the other hand, fast-growing corals like Acropora and Montipora may require more attention, primarily by pruning or fragging, to maintain their size and shape within the aquarium.

Environmental factors like temperature, lighting, and water chemistry also influence the growth rates of corals. Ensure that your reef tank’s conditions align with your chosen corals’ optimal growth parameters for the best results.


Stepping into the realm of reef aquariums is a commitment to becoming a steward of a miniaturized ocean ecosystem, nurturing and observing its evolution over time. Selecting the right corals for your reef tank is a nuanced task, requiring a keen understanding of the corals’ needs and the conditions within your tank. But with careful consideration of compatibility, placement, care, and an understanding of your tank’s specific parameters, you can cultivate a thriving reef tank.

Although this may seem daunting at first, the reward is a living piece of oceanic art that evolves, grows, and thrives under your care. Remember, a successful reef tank isn’t merely about having the most beautiful or exotic corals but about creating a balanced, harmonious, and sustainable ecosystem that mirrors the beauty and diversity of our world’s coral reefs. With the knowledge you’ve gained from this guide, you’re now well-prepared to embark on this exciting journey. Happy reefing!