TYPES OF CORAL FOR REEF TANKS

Soft Corals: The Resilient Entry Point

Soft corals, or Alcyonaceans, are widely considered the perfect starting point for beginner reefers. Unlike their stony cousins, these corals do not produce a rigid calcium carbonate skeleton. Instead, they utilize tiny, needle-like structures called sclerites for support. This flexible anatomy makes them incredibly hardy and capable of withstanding the minor fluctuations in water quality that are common in new tanks. They are often characterized by their flowing, rhythmic movements, which add a dynamic sense of life to the aquarium that rigid corals cannot replicate.

One of the most popular choices in this category is the Zoanthid. Often called Zoas, these colonial polyps come in nearly every color combination imaginable and are famous for their fast growth rates. Another staple is the Leather Coral (Sarcophyton), which develops a mushroom-like cap that provides a perfect perch for certain fish like the Lawnmower Blenny. While soft corals are generally forgiving, it is vital to remember that the process of cycling a fish tank must be fully completed before introducing any coral, as they are highly sensitive to even trace amounts of ammonia. Soft corals are also known for chemical warfare, releasing toxins into the water to inhibit the growth of nearby rivals, so adequate spacing and the use of activated carbon are essential hacks for success.

• Zoanthids: Tiny, colorful buttons that spread quickly over rockwork.
• Green Star Polyps (GSP): Known for their neon green color and grass-like appearance; very hardy but can be invasive.
• Pulsing Xenia: Famous for their polyps that open and close rhythmically, though they require stable iodine levels.
• Leather Corals: Large, durable corals that resemble terrestrial mushrooms or cabbages.
• Mushrooms (Discosoma): Low-light specialists that thrive in the shaded areas of the tank.

LPS Corals: The Bold and the Beautiful

Large Polyp Stony (LPS) corals represent the middle ground between the ease of soft corals and the demanding nature of high-end stony corals. These corals have a hard skeleton but are topped with large, fleshy polyps that can extend several inches. Because of their fleshy nature, LPS corals are incredibly interactive to watch; they change size throughout the day and often display long sweeper tentacles at night to catch floating particles. This makes them a favorite for intermediate hobbyists who want a more diverse and colorful reef without the extreme technical requirements of SPS corals.

The Euphyllia family is the crown jewel of the LPS world, consisting of Hammer, Torch, and Frogspawn corals. These species have long, flowing tentacles that sway in the current and are often used by Ocellaris Clownfish as a substitute for an anemone. However, LPS corals require more attention to mineral levels. They rely on Calcium and Alkalinity to build their skeletons, and failing to maintain these levels can lead to tissue recession, where the flesh peels away from the bone. Monitoring the dangers of high ammonia, nitrite and nitrate is also critical, though many LPS corals actually prefer slightly dirty water with detectable nitrates (around 5-10 ppm) to fuel their fleshy growth.

A common beginner mistake with LPS corals is placing them in areas of high flow. Because their tissue is so heavy and filled with water, a strong, direct blast from a powerhead can tear the flesh against the sharp edges of their own skeleton. Always aim for indirect flow that makes the tentacles shimmer rather than whip violently. Feeding is also a great way to boost LPS health; target-feeding them with mysis shrimp or specialized coral pellets once a week can lead to massive growth spurts and more vibrant colors.

• Hammer Corals: Distinguished by their anchor-shaped tips and vibrant greens or golds.
• Torch Corals: Highly prized for their long, flowing tentacles that mimic sea anemones.
• Candy Cane Corals: A great starter LPS with easy-to-fragment branching skeletons.
• Acanthastrea (Acans): Low-growing, donut-shaped corals with incredible rainbow color patterns.
• Elegance Coral: A stunning, large-polyped species that requires a sand-bed placement.

SPS Corals: The High-End Architects

Small Polyp Stony (SPS) corals are often considered the final boss of the reef-keeping world. These corals, such as Acropora and Montipora, consist of thin layers of tissue stretched over dense, complex skeletons. In the wild, they are the primary builders of the reef crest, thriving in areas of intense sunlight and crashing waves. In the home aquarium, they demand perfect water stability, high-intensity LED or T5 lighting, and massive amounts of random, turbulent flow. They are far less forgiving than other corals; a single day of high temperature or a swing in alkalinity can lead to Rapid Tissue Necrosis (RTN), where the coral dies within hours.

For the intermediate reefer looking to try SPS for the first time, the Montipora genus is the best entry point. Monti Caps grow in beautiful, swirling plating patterns and are significantly hardier than the branching Acropora. Birdsnest corals (Seriatopora) are another great choice, as they grow very quickly and provide a dense thicket for small fish like Blue-Green Chromis to hide in. To keep SPS corals, you must be prepared to test your water parameters at least twice a week. They require very low nutrient levels, as high phosphates will inhibit their ability to calcify and turn their vibrant neon colors into a dull, muddy brown.

• Acropora: The most iconic and demanding coral; requires peak lighting and flow.
• Montipora: Available in plating, encrusting, or branching forms; great for SPS beginners.
• Birdsnest Coral: Grows in thin, interlocking branches that create a complex habitat.
• Pocillopora: A hardy, fuzzy-looking SPS that can actually spawn in the home aquarium.
• Stylophora: Often called Milka corals, they feature thick, rounded branches and deep purples.

Compatibility and Chemical Warfare in the Reef

One of the most overlooked aspects of building a reef is coral compatibility. Just because two corals look beautiful together doesn't mean they can live in close proximity. Corals are highly competitive animals. LPS corals like Torches have sweeper tentacles that can extend up to six inches at night, stinging and killing any neighboring coral that gets too close. Soft corals, on the other hand, engage in allelopathy, releasing chemical compounds into the water column to stunt the growth of rivals. When planning your reef, always research the basics of fish compatibility alongside your coral placement to ensure your fish won't nip at your new investments.

Specific fish species can be reef safe or reef safe with caution. For example, Tangs (like the Yellow or Kole Tang) are excellent for a reef because they eat the algae that would otherwise smother the corals. However, many Butterflyfish and Angelfish consider coral polyps a natural delicacy. Even reef safe invertebrates like certain Emerald Crabs or Starfish can sometimes turn on corals if they are not well-fed. A balanced reef requires a Cleanup Crew (CUC) that targets nuisance algae and detritus without bothering the delicate tissues of your SPS or LPS specimens. Ensure you have plenty of snails, such as Trochus or Cerith, to keep the glass and rocks clean.

• Zone Placement: Place aggressive LPS with long sweepers far from sensitive neighbors.
• Carbon Usage: Run high-quality activated carbon to soak up chemical toxins released by soft corals.
• Fish Selection: Avoid Flame Angels or Coral Beauties if you are keeping expensive LPS, as they are known nippers.
• Vertical Hierarchy: Place light-hungry SPS at the top and shade-loving Mushrooms at the bottom.
• Dipping New Corals: Always use a coral dip to prevent pests like flatworms or nudibranchs from entering the tank.

Actionable Care Tips for a Flourishing Reef

As you move from a beginner softie tank to a mixed reef, your maintenance routine must evolve. In a tank with many stony corals, the inhabitants will physically pull Calcium (Ca), Magnesium (Mg), and Carbonate (Alkalinity) out of the water to build their skeletons. Standard water changes may not be enough to replenish these elements. Intermediate hobbyists often utilize 2-part dosing or Kalkwasser to maintain stability. Keeping your Alkalinity stable is the holy grail of reef keeping; a swing of even 1.0 dKH in a 24-hour period can cause significant stress.

Lighting is another area where precision matters. Not all blue light is the same. Corals rely on specific wavelengths of light to fuel the zooxanthellae (algae) living in their tissues. Using a PAR meter to map your tank is a pro move that allows you to place corals in their sweet spot rather than guessing. If your light is too intense, the coral will bleach, turning white as it expels its algae. If the light is too dim, the coral will turn brown as it overproduces algae to compensate. A photo-period of 8 to 10 hours, with a slow ramp-up and ramp-down to simulate sunrise and sunset, is the best way to prevent stress and encourage natural growth cycles.

• Maintain Magnesium: Keep Mg around 1350 ppm to allow Calcium and Alkalinity to stay in solution.
• Target Feeding: Use a pipette to feed LPS corals at night when their tentacles are fully extended.
• Auto Top-Off (ATO): Use an ATO to prevent salinity swings caused by evaporation.
• Refugium: Grow macroalgae like Chaetomorpha in your sump to stabilize pH and export nitrates.
• Observation: Spend 10 minutes a day just looking at your corals; they will tell you if they are unhappy before your test kits do.

Takeaway: Your Journey to a Masterpiece Reef

Building a successful reef tank is a testament to the hobbyist's patience, observation, and technical skill. Whether you choose the flowing simplicity of a Soft Coral garden, the bold textures of an LPS-dominant tank, or the architectural challenge of an SPS reef, each coral type offers a unique window into the complexity of the ocean. By prioritizing water stability, respecting coral zones, and choosing tank mates that support the ecosystem, you can transform your home into a sanctuary for these incredible organisms. Remember that every reef is a work in progress; there will be setbacks, but each challenge is an opportunity to learn more about the delicate balance of aquatic life. Are you ready to take the plunge and select your first signature coral? Explore our deep-dive equipment reviews and species profiles at RateMyFishTank.com to find the perfect match for your system! If you found this guide helpful, why not join our forums and share a photo of your current setup with our community of experts? Your journey to a masterpiece reef starts with a single, healthy frag.