Can Coral Be Placed Directly on Live Rock in Reef Tanks?
The placement of coral on live rock requires careful consideration based on coral type, rock characteristics, and tank conditions. Here’s a detailed analysis:
1. Compatibility with Coral Types
- LPS Corals (e.g., Pocillopora damicornis): Can tolerate direct contact with live rock but require stable placement to avoid falling. Their larger polyps may trap debris, necessitating moderate water flow to prevent decay.
- SPS Corals (e.g., Montipora): Typically attach to rocks naturally in the wild. However, aggressive SPS varieties may chemically attack neighboring corals if placed too closely.
- Soft Corals (e.g., Mushrooms): Often thrive on live rock due to their flexible bases, but some species (like Zoanthids) prefer sandy substrates to spread.
2. Live Rock Preparation
- Stability: Ensure rocks are securely stacked to prevent shifting, especially for heavy LPS corals. Smaller fragments can be glued with epoxy for safety.
- Chemical Safety: Test rocks for contaminants (e.g., copper) before use, as toxins can leach into the water and harm coral6.
3. Best Practices
- Lighting Adaptation: Place corals initially in low-light zones (e.g., PAR 100) and gradually adjust to prevent bleaching. For example, button corals (Palythoa) need acclimation to avoid stress.
- Spacing: Maintain 5–10 cm gaps between aggressive corals to minimize territorial conflicts.
- Water Flow: Moderate to high flow helps remove waste from coral crevices, reducing the risk of necrosis.
4. Alternatives to Direct Placement
- Frag Plugs: Smaller coral fragments can be secured onto ceramic plugs before being placed on rocks, ensuring stability.
- Sand Beds: Some species (e.g., Duncanopsammia) thrive better when embedded in sand rather than on rocks.
Conclusion: While many corals can be placed directly on live rock, success depends on species-specific needs, rock quality, and tank management. Prioritize stability, water chemistry, and gradual acclimation for optimal results.