Coral fragging has transformed from a niche aquarium practice into a vital technique supporting both hobbyist reef tanks and large-scale restoration efforts. I've spent years perfecting these techniques, and today I'll share everything you need to know about safely and effectively propagating corals in your home aquarium.
Whether you're looking to share coral with fellow reefers, manage overgrowth in your tank, or contribute to conservation efforts, understanding proper fragging techniques is essential. According to the Birch Aquarium at Scripps, which has over 25 years of coral propagation experience, proper fragging techniques can significantly improve survival rates and growth speeds of coral fragments.
The process might seem intimidating at first, but with the right knowledge and tools, you'll discover that fragging is one of the most rewarding aspects of reef keeping. Let's explore the science, techniques, and best practices that will help you successfully propagate your corals.
Understanding Coral Biology and Fragging Fundamentals
Before picking up any tools, it's crucial to understand what makes coral fragging possible. Corals are colonial organisms composed of thousands of individual polyps, each genetically identical to the others. This unique biology allows a single fragment to grow into a complete colony under the right conditions.
When we frag corals, we're essentially exploiting their natural ability to recover from damage and regenerate. In the wild, storms, predation, and other disturbances regularly break corals apart, with fragments settling elsewhere to form new colonies. This asexual reproduction method has been occurring for millions of years.
The NOAA Coral Reef Conservation Program, which coordinates with numerous aquariums and research facilities, notes that understanding coral growth patterns is fundamental to successful propagation. Different coral types heal and grow at varying rates, which directly impacts fragging success.
Types of Corals and Their Fragging Requirements
SPS (Small Polyp Stony) Corals
SPS corals like Acropora, Montipora, and Stylophora are among the most commonly fragged corals. Their branching growth patterns make them ideal candidates for propagation. These corals have dense calcium carbonate skeletons that require specific cutting techniques.
When fragging SPS corals, I've found that clean, quick cuts are essential. The skeleton is hard but brittle, and improper technique can cause unnecessary stress or damage. Recovery typically takes 2-4 weeks, with new tissue growth visible within days under optimal conditions.
Research published by Baums (2008) on coral reproduction highlights that while SPS fragging is highly successful, maintaining genetic diversity in captive populations requires careful planning. This is particularly important for conservation-minded aquarists.
LPS (Large Polyp Stony) Corals
LPS corals such as hammer corals, torch corals, and brain corals present unique fragging challenges. Their larger, fleshier polyps and different skeletal structures require modified approaches. Some LPS corals naturally form distinct heads that can be separated, while others need more careful sectioning.
Working with LPS corals demands extra patience. Their soft tissue is more prone to damage, and healing times are generally longer than SPS corals. I typically wait 3-6 weeks before considering an LPS frag fully recovered.
For those interested in specific LPS propagation, understanding individual species requirements is crucial. Our guide on frogspawn coral care covers propagation techniques for this popular LPS species in detail.
Soft Corals
Soft corals like leather corals, zoanthids, and mushrooms are perhaps the most forgiving for beginners. Without rigid skeletons, these corals can often be fragged with simple cutting tools or even by hand in some cases.
The main consideration with soft coral fragging is managing the toxins many species release when stressed. Activated carbon filtration and good water flow become especially important during and after fragging sessions. Recovery is typically rapid, with most soft corals healing within 1-2 weeks.
Essential Tools and Equipment for Coral Fragging
Having the right tools makes fragging safer, more efficient, and less stressful for both you and your corals. Here's what I use in my fragging station:
Cutting Tools
Bone cutters or coral cutters: These specialized tools are essential for SPS and branching LPS corals. Quality matters here - dull blades crush rather than cut, causing unnecessary damage. I recommend stainless steel cutters that can be properly sterilized between uses.
Band saw or tile saw: For larger colonies or precise cuts through thick skeletons, a wet band saw provides clean, straight cuts. While not necessary for beginners, serious fraggers find these tools invaluable. Always use a saw designed for wet cutting to prevent overheating.
Scalpel or razor blade: Soft corals and some LPS corals are best cut with sharp blades. Fresh, sterile blades for each fragging session prevent disease transmission between colonies.
Dremel or rotary tool: Useful for scoring and breaking certain corals or creating specific shapes. The precision these tools offer is particularly helpful for valuable or delicate specimens.
Safety Equipment
Safety glasses or goggles: Non-negotiable when fragging. Coral fragments can fly unexpectedly, and many species release toxins that can severely irritate eyes. I learned this lesson the hard way early in my reef keeping journey.
Nitrile gloves: Protection from coral toxins, sharp skeletons, and potential pathogens. Some corals, particularly zoanthids, contain palytoxin, one of the most potent natural toxins known. Never handle these species without gloves.
Activated carbon mask: When using power tools or fragging toxic species, respiratory protection prevents inhalation of coral dust or aerosolized toxins. This is especially important in enclosed spaces.
Apron or protective clothing: Coral mucus and fragments can stain and irritate skin. Dedicated fragging clothes save your regular wardrobe and provide an extra barrier against toxins.
Mounting Supplies
Frag plugs or discs: Ceramic or aragonite-based plugs provide stable bases for coral fragments. I prefer aragonite as it integrates naturally with coral skeleton over time.
Cyanoacrylate glue (super glue gel): The gel formula stays in place better underwater. Ensure you're using reef-safe, cyanoacrylate-only formulas without additives.
Epoxy putty: Two-part aquarium-safe epoxy works well for larger frags or irregular shapes. It takes longer to cure but provides stronger initial hold.
Rubber bands: Natural rubber bands work for temporarily securing soft corals or LPS to rocks. They degrade over time as the coral attaches naturally.
Support Equipment
Fragging container: A shallow container filled with tank water for working on corals. This keeps specimens submerged and reduces stress during the fragging process.
Turkey baster or pipette: For removing debris and detritus from fresh cuts. Clean cuts heal faster and are less prone to infection.
Iodine dip solution: Many fraggers use diluted iodine solutions to disinfect fresh cuts and prevent infection. Follow manufacturer recommendations for concentration.
Step-by-Step Fragging Techniques
Preparation Phase
Success in coral fragging starts before making any cuts. First, assess your coral's health - only frag healthy, well-established colonies. Stressed or recovering corals should be left alone until fully rehabilitated.
Set up your fragging station with all tools cleaned and laid out. Fill your fragging container with water from the display tank to maintain consistent parameters. Having everything ready minimizes the time corals spend out of optimal conditions.
Plan your cuts carefully. Examine the coral's growth pattern and identify natural breaking points or areas where cuts will cause minimal damage. For branching corals, look for narrow points between branches. For encrusting species, identify areas where the coral has grown beyond its original substrate.
SPS Coral Fragging Process
Remove the coral from your display tank and place it in the fragging container. For Acropora and similar branching species, identify branches at least 1-2 inches long for best results. Position your cutters at the base of the selected branch.
Make a swift, clean cut with steady pressure. Avoid crushing or twisting motions that can damage surrounding tissue. For thicker branches, score around the circumference first, then snap cleanly. This technique reduces stress on the parent colony.
Immediately after cutting, rinse both the fragment and parent colony with tank water to remove any loose tissue or skeleton particles. Mount the fragment promptly - exposed skeleton is prone to algae growth and infection.
Apply a small amount of gel super glue to the frag plug, then press the coral fragment firmly for 10-15 seconds. The glue cures quickly in water, forming a strong bond. Return the parent colony to the display tank and place the frag in an appropriate location with similar flow and lighting.
LPS Coral Fragging Process
LPS fragging requires more finesse due to their larger polyps and softer tissue. For branching LPS like hammer or torch corals, identify natural separation points between heads. These corals often have distinct skeletal branches that can be separated.
Using bone cutters or a saw, cut through the skeleton well below the flesh line. This extra skeleton provides a handle for mounting and reduces tissue damage. For brain corals or others with continuous skeletons, use a wet saw to make clean sections.
After cutting, gently rinse the fragments and inspect for tissue damage. LPS corals benefit from a brief iodine dip (following product instructions) to prevent infection. Mount using epoxy putty for larger pieces or super glue for smaller fragments.
Place LPS frags in lower flow areas initially, gradually moving them to final positions as they heal. These corals are more prone to brown jelly disease after fragging, so monitor closely for the first week.
Soft Coral Fragging Process
Soft coral fragging is generally more forgiving but requires attention to toxin management. For leather corals, use a sharp scalpel to cut through the tissue in one smooth motion. Avoid sawing motions that increase toxin release.
Zoanthids and palythoas require extreme caution due to palytoxin. Always wear gloves and eye protection, work in well-ventilated areas, and never handle these corals if you have open cuts. Cut between polyps when possible to minimize damage.
Mushroom corals can often be fragged by cutting them in half or quarters, with each piece regenerating into a complete mushroom. Some aquarists use the less invasive technique of scoring the surface, encouraging the mushroom to split naturally.
Soft coral fragments typically attach themselves if placed in low flow areas. Alternatively, use rubber bands or bridal veil netting to secure them until natural attachment occurs. This process usually takes 1-2 weeks.
Critical Safety Protocols and Best Practices
Toxin Management
Coral toxins are a serious concern that many beginners underestimate. Palytoxin, found in zoanthids and palythoas, can cause severe symptoms including difficulty breathing, muscle pain, and heart problems. Even experienced reefers have been hospitalized from palytoxin exposure.
Always assume corals are toxic until proven otherwise. Work in well-ventilated areas, never boil rocks with coral attached, and avoid creating aerosols when fragging. If you experience unusual symptoms after fragging, seek medical attention immediately and inform healthcare providers about coral exposure.
Running activated carbon during and after fragging sessions helps remove toxins from your system. Increase protein skimming and perform a water change within 24-48 hours of major fragging sessions to maintain water quality.
Disease Prevention
Cross-contamination between colonies is a real risk during fragging. Sterilize tools between different corals using isopropyl alcohol or a diluted bleach solution followed by thorough rinsing. Never use the same blade on multiple colonies without proper sterilization.
Quarantine new frags before adding them to display tanks, especially when receiving frags from other systems. A 2-4 week observation period can prevent introducing pests or diseases to your established colonies.
The Association of Zoos and Aquariums emphasizes that disease prevention protocols are crucial for maintaining healthy captive coral populations. Their guidelines recommend treating all frags as potential disease vectors until proven healthy.
Environmental Considerations
Maintain stable water parameters during fragging. Stressed corals are more susceptible to infection and slower to heal. Test alkalinity, calcium, and magnesium before major fragging sessions, as healing corals consume these elements at increased rates.
Avoid fragging during tank cycling, after major changes, or when parameters are unstable. Similarly, don't frag multiple colonies simultaneously if your system can't handle the bioload from stressed corals.
Temperature control is critical. Keep fragging sessions brief to prevent temperature fluctuations in holding containers. Use heaters in fragging containers for extended sessions, maintaining temperature within 1°F of your display tank.
Post-Fragging Care and Recovery
The first 48 hours after fragging are critical for coral recovery. Monitor frags closely for signs of tissue recession, bleaching, or infection. Healthy frags should show polyp extension within 24-48 hours, though full extension may take longer.
Maintain pristine water quality during recovery. I perform 10% water changes every other day for the first week after major fragging sessions. This dilutes any toxins released and replenishes trace elements consumed during healing.
Adjust flow around new frags to prevent them from being blown over while avoiding dead spots where detritus can accumulate. Many fraggers use frag racks that position corals optimally while keeping them stable during recovery.
Feeding can accelerate recovery. Target feed frags with appropriate foods - amino acids for SPS, meaty foods for LPS, and phytoplankton for many soft corals. Start feeding 2-3 days after fragging once polyps are extending normally.
Document growth and recovery rates. Photographing frags weekly helps track progress and identify problems early. This documentation is particularly valuable for rare or expensive corals where optimizing growth conditions is crucial.
Advanced Techniques and Considerations
Growth Optimization
Strategic fragging can actually accelerate overall coral growth. By fragmenting a colony into multiple pieces, you increase the number of growth edges, potentially multiplying your coral mass more quickly than letting a single colony grow.
Mounting orientation affects growth patterns. Horizontal mounting encourages encrusting growth, while vertical mounting promotes branching in many species. Experiment with different orientations to achieve desired growth forms.
Some aquarists practice "pruning" rather than traditional fragging, regularly trimming fast-growing species to maintain desired shapes and prevent overshadowing of other corals. This technique requires understanding each species' growth patterns and recovery rates.
Conservation and Ethical Considerations
The Marine Breeders Initiative encourages hobbyists to view fragging as part of coral conservation. By propagating corals in captivity, we reduce collection pressure on wild reefs while maintaining genetic resources for potential restoration efforts.
However, Knowlton (2001) cautions that captive propagation must maintain genetic diversity. Continuously fragging the same colonies can create genetic bottlenecks. Serious conservation-minded aquarists should maintain multiple genetic lines of each species.
Consider participating in coral banking programs or frag swaps that promote genetic diversity. Many aquarium societies coordinate these efforts, creating networks of hobbyists maintaining diverse coral populations.
Mote Marine Laboratory, which plants thousands of coral fragments annually in restoration projects, demonstrates how hobbyist fragging techniques scale to conservation efforts. Their success shows that skills developed in home aquariums have real conservation value.
Troubleshooting Common Fragging Problems
Tissue Recession
If coral tissue recedes from cut edges, check water parameters immediately. Low alkalinity is often the culprit, as healing corals consume carbonates rapidly. Maintain alkalinity between 8-11 dKH during recovery.
Excessive flow can also cause recession. Reduce flow around affected frags and gradually increase it as healing progresses. Some corals benefit from temporary placement in lower flow refugium areas during initial recovery.
Slow or No Attachment
When frags won't attach to plugs, the mounting surface may be the issue. Roughen smooth surfaces with sandpaper to provide better grip for coral tissue. Some aquarists score patterns into frag plugs to encourage faster encrustation.
Check that glue or epoxy fully cured before placing frags in water. Uncured adhesives can prevent proper attachment and potentially release toxins. If in doubt, let mounted frags cure in a separate container before adding to your system.
Infection or Brown Jelly
Brown jelly disease occasionally affects fragged corals, particularly LPS species. If detected early, affected tissue can be siphoned away and the coral treated with an iodine dip. Increase flow around infected corals to prevent disease spread.
Prophylactic dipping in coral disinfectants can prevent many infections. Products containing iodine or other antimicrobials, used according to directions, significantly reduce infection risk without harming coral tissue.
Bleaching After Fragging
Stress-induced bleaching sometimes occurs after fragging. Reduce lighting intensity by 30-50% for recovering frags, gradually returning to normal levels over 2-3 weeks. Ensure temperature remains stable, as thermal stress compounds fragging stress.
Feed bleached frags more frequently to provide energy while zooxanthellae populations recover. Amino acid supplements can particularly help during this recovery phase.
Building Your Fragging System
Dedicated fragging systems improve success rates and make the process more efficient. A basic setup includes a shallow tank (10-20 gallons), appropriate lighting, flow pumps, and heating. This system shares water with your display through a common sump or can operate independently.
Frag tank lighting doesn't need to match display intensity initially. Many fraggers use adjustable LED fixtures to provide varying intensities as frags acclimate and grow. T5 fixtures also work well, providing even coverage across frag racks.
Flow patterns in frag tanks differ from display tanks. Laminar flow across frag racks prevents dead spots while avoiding excessive force that could dislodge healing frags. Programmable powerheads allow flow adjustments as frags develop.
Consider adding a quarantine/observation section to your fragging system. This isolated area lets you monitor new frags or treat problems without affecting other corals. A simple divider in your frag tank can serve this purpose.
Economic Aspects of Coral Fragging
Fragging can offset reef keeping costs or even generate income. Many local fish stores offer credit for coral frags, and online marketplaces connect fraggers with buyers nationwide. However, success requires understanding market demand and maintaining quality.
Track your costs carefully. Factor in equipment, supplies, utilities, and time when pricing frags. Many beginning fraggers underestimate true costs, leading to unsustainable pricing that ultimately harms the hobby marketplace.
Build reputation through consistent quality and honest representation. Photograph frags accurately, disclose any issues, and guarantee live arrival when shipping. The reef keeping community values integrity, and reputation directly impacts fragging success.
Consider specializing in specific coral types or rare varieties. While common corals have steady demand, developing expertise with challenging or unusual species can command premium prices and establish you as a valuable resource in the community.
Frequently Asked Questions
How long should I wait before fragging a new coral?
Wait at least 3-4 months after adding a new coral to your system before fragging. This allows time for acclimation, recovery from shipping stress, and establishment of healthy growth patterns. Rushing to frag new additions often results in poor recovery or colony loss.
Can I frag corals that are touching or fighting?
Yes, fragging is actually an excellent solution for coral warfare. Carefully separate the corals and frag any damaged sections. Clean cuts heal better than chemical burn damage from coral warfare. Place frags far from aggressive species during recovery.
What's the minimum size for viable frags?
This varies by species. SPS frags should be at least 0.75-1 inch, LPS need 1-2 polyps minimum, and soft corals can survive as quite small pieces. Larger frags generally have better survival rates and grow faster than minimum-sized pieces.
How many frags can I make from one colony?
Never remove more than 25-30% of a healthy colony at once. This ensures the parent colony recovers quickly and maintains its health. For valuable or slow-growing corals, take even less. You can frag again after the colony fully recovers, typically 2-3 months later.
Should I dip all frags before mounting?
While not always necessary for frags from your own system, dipping provides extra protection against infection. Always dip frags received from other systems or when fragging stressed corals. Use coral-specific dips according to manufacturer instructions.
Can I frag corals during spawning season?
Avoid fragging corals showing signs of spawning preparation or recent spawning. The energy demands of reproduction combined with healing stress can overwhelm corals. Wait at least 2-3 weeks after spawning events before fragging.
What's the best season for fragging?
In stable indoor systems, you can frag year-round. However, many aquarists prefer spring and early summer when growth rates naturally increase. Avoid fragging during tank moves, equipment changes, or other stressful events.
How do I know if a frag is ready to sell or trade?
Frags should be fully healed, showing normal polyp extension and coloration, and demonstrating new growth beyond the original cut. This typically takes 4-6 weeks minimum. Selling unhealed or stressed frags damages your reputation and harms recipient success.
Conclusion
Coral fragging combines art, science, and conservation in one of reef keeping's most rewarding practices. Through careful technique and attention to detail, we can propagate these remarkable animals while supporting both our hobby and coral conservation efforts worldwide.
The techniques I've shared come from years of experience and learning from the broader reef keeping community. Each coral teaches us something new, and sharing these lessons strengthens our collective knowledge. As you develop your fragging skills, remember that patience and observation are your best tools.
The future of coral reefs, both in our aquariums and in nature, depends on successful propagation techniques. By mastering coral fragging, you're not just growing your reef tank - you're participating in the preservation of these incredible ecosystems for future generations.
Whether you're fragging to manage growth, share with fellow reefers, or contribute to conservation efforts, approach each cut with respect for these living creatures. With proper technique, safety protocols, and patience, you'll find coral fragging becomes one of the most satisfying aspects of reef keeping.
