Understanding Different Types of Corals:

A Comprehensive Overview for Saltwater Hobbyists

Corals are the vibrant, living jewels of the ocean, and they play a crucial role in the health of marine ecosystems. For saltwater hobbyists, understanding the different types of corals and their specific needs is essential for creating a thriving reef tank. This guide will dive into the three main categories of corals: soft corals, LPS (Large Polyp Stony), SPS (Small Polyp Stony), along with examples, identification tips, and care requirements.

Soft Corals

Check out our Article on Soft Corals for a deeper dive: Comprehensive Guide to Soft Corals

Soft corals lack the hard calcium carbonate skeletons found in SPS and LPS corals. Instead, they have flexible, fleshy bodies supported by a protein matrix. They are generally considered the easiest corals to care for and are well-suited for beginners.

Identification:

• Appearance: Soft corals have a wide range of forms, from branching and encrusting to leafy and finger-like structures. They often exhibit vibrant colors and may contain sclerites (tiny skeletal elements) for support.
• Examples:
  • Mushrooms (Corallimorphs): Disc-shaped polyps that can spread rapidly. Examples include Rhodactis and Discosoma.
  • Zoanthids: Colonial polyps that form mats or encrustations. They come in various colors and patterns.
  • Leathers: Corals with a leathery texture, such as Toadstool (Sarcophyton) and Finger Leather (Sinularia).
  • Xenia: Pulsing corals that have a distinctive rhythmic movement of their polyps.
  • Clavularia (Clove Polyps): Colonial corals with small, flower-like polyps.

Care Requirements:

• Water Quality: Soft corals are more tolerant of varying water conditions but still require regular maintenance to ensure stable parameters.
• Flow: They prefer moderate to low water flow, which helps keep their polyps extended and removes waste without causing damage.
• Lighting: Soft corals thrive under moderate lighting conditions. They can adapt to lower light levels, making them suitable for various tank setups.
• Feeding: While soft corals rely heavily on photosynthesis, some species can benefit from supplemental feedings of planktonic or dissolved organic matter.

Large Polyp Stony (LPS) Corals

Check out our Article on LPS Corals for a deeper dive: Comprehensive Guide to LPS Corals

LPS corals are characterized by their larger polyps and more massive skeletal structures. They are generally easier to care for than SPS corals but still require attention to water quality and lighting.

Identification:

• Appearance: LPS corals have large, fleshy polyps that can extend significantly from their skeletons. They often exhibit vibrant colors and striking patterns.
• Examples:
  • Euphyllia: Includes species like Hammer (Euphyllia ancora), Torch (Euphyllia glabrescens), and Frogspawn (Euphyllia divisa).
  • Acanthastrea: Known for their fleshy polyps and bright, contrasting colors.
  • Favia: Often have a brain-like appearance with prominent ridges and valleys.

Care Requirements:

• Water Quality: LPS corals prefer stable water conditions with slightly higher nutrient levels than SPS corals. Regular water changes and monitoring are essential.
• Flow: They require moderate water flow to keep their polyps gently moving, ensuring waste removal and nutrient delivery without causing tissue damage.
• Lighting: LPS corals thrive under moderate to high lighting. They can adapt to various lighting conditions, but it's important to acclimate them slowly to prevent bleaching.
• Feeding: LPS corals benefit from direct feedings of meaty foods, such as mysis shrimp or specialized coral foods, in addition to their photosynthetic capabilities.

Small Polyp Stony (SPS) Corals

Check out our Article on SPS Corals for a deeper dive: Mastering SPS Corals

SPS corals are known for their small polyps and hard, calcium carbonate skeletons. They are often considered the most challenging corals to keep due to their specific requirements for water quality, flow, and lighting.

Identification:

• Appearance: SPS corals have small, closely spaced polyps that extend from a hard, often branching skeleton. They come in various shapes, such as branching, plating, and encrusting forms.
• Examples:
  • Acropora: Branching structures with vibrant colors. Commonly referred to as "Acros."
  • Montipora: Can be plating, encrusting, or branching with various colors and patterns.

Care Requirements:

• Water Quality: SPS corals demand pristine water conditions with low levels of nitrates and phosphates. Regular testing and maintaining stable parameters are crucial.
• Flow: They require strong, turbulent water flow to mimic their natural reef environment and to ensure the removal of waste and delivery of nutrients.
• Lighting: SPS corals need high-intensity lighting, often provided by metal halides or high-quality LED lights. They thrive under a spectrum that closely mimics natural sunlight.
• Feeding: While SPS corals primarily rely on photosynthesis through their symbiotic algae (zooxanthellae), they can benefit from supplemental feedings of planktonic foods.

Water Quality, Flow, and Lighting for Different Coral Types

Maintaining the appropriate water quality, flow, and lighting is crucial for the health and growth of all coral types.

• Water Quality: Regular testing and maintaining stable parameters for calcium, alkalinity, magnesium, nitrate, and phosphate levels are essential. Aim for:

  • Calcium: 400-450 ppm
  • Alkalinity: 8-12 dKH
  • Magnesium: 1250-1350 ppm
  • Nitrate: <5 ppm for SPS, <10 ppm for LPS and soft corals
  • Phosphate: <0.03 ppm for SPS, <0.1 ppm for LPS and soft corals

• Flow: Adjust the water flow to suit the specific needs of your corals. SPS corals need strong, turbulent flow, while LPS and soft corals thrive in moderate to low flow environments.

• Lighting: Use appropriate lighting systems to meet the needs of your corals. SPS corals require high-intensity lighting, LPS corals thrive under moderate to high lighting, and soft corals do well under moderate lighting conditions.

Conclusion

Understanding the different types of corals and their specific needs is key to creating a thriving reef tank. By providing the appropriate water quality, flow, and lighting, and understanding the unique requirements of SPS, LPS, and soft corals, you can ensure a healthy and vibrant marine ecosystem.

Happy Reefing!