Acropora are among the most popular small polyp stony (SPS) corals to propagate, and healthy colonies can produce new frags through careful cutting of established branches. Unlike soft corals such as mushrooms, Acropora produce a rigid calcium carbonate skeleton. This makes the actual cutting process considerably different, and healthy branches can often be separated cleanly and immediately mounted to a new substrate.

Successful Acropora fragging starts well before the first cut. The parent colony should be healthy, actively growing, and established in a stable aquarium before you attempt to propagate it.

In this guide, we'll cover everything you need to know about fragging Acropora, including when a colony is ready, the tools you'll need, how to make clean cuts, how to mount new frags, and what to expect during recovery.

What Are Acropora Corals?

Acropora are a genus of small-polyp stony (SPS) corals belonging to the family Acroporidae. Unlike soft corals, Acropora produce a rigid calcium carbonate skeleton that provides the structure for their growth. Depending on the species and variety, Acropora can form branching, tabling, bushy, or encrusting colonies.

What Makes Acropora Different From Other Corals?

Acropora are generally considered advanced reef corals because they tend to be less tolerant of environmental instability than many soft corals and large polyp stony (LPS) corals.

Their growth process is primarily characterized by depositing new calcium carbonate skeleton, meaning a healthy colony can produce noticeable amounts of new growth when provided with appropriate lighting, flow, nutrients, and stable water chemistry. That growth is what makes many Acropora excellent candidates for coral propagation once aquarium water chemistry is consistently stable over weeks, months, or even years.

SPS corals in general are sensitive to parameter swings and chemical instability in the water, and Acropora are known to be on the more sensitive end of that spectrum. This holds especially true during the fragging process when stress levels are generally elevated. This means that, while that actual process of fragging Acropora is often comparatively simple, the unyielding stability requirements of Acropora can make the fragging process more demanding than those of more resilient corals.

Common Acropora Growth Forms

Acropora can take several different growth forms, including:

Branching Acropora
Bushy Acropora
Tabling Acropora
Encrusting Acropora

The easiest Acropora to frag are generally branching varieties because individual branches can be separated from the colony without cutting through a large portion of the main structure. This process is typically done with the use of bone cutters.

Other growth forms can still be propagated, but the appropriate technique depends on the shape and structure of the colony. For this guide, we'll focus primarily on branching Acropora, where individual branches can be removed and mounted as new frags.

When Should You Frag an Acropora?

Acropora should only be fragged when the parent colony is healthy, actively growing, and not exhibiting any signs of stress.

A healthy Acropora colony should generally have:

Consistent polyp extension
Healthy coloration
Good tissue coverage
Visible growth
New branch development
Stable attachment to its substrate
Stable aquarium conditions

A colony that has recently been acquired or moved should be given time to establish itself before being fragged. This holds especially true for Acropora because they are so sensitive to stress and parameter changes.

Avoid fragging Acropora that has:

Recently been shipped
Recently been introduced to your aquarium
Signs of bleaching
Tissue recession
Slow tissue necrosis (STN)
Rapid tissue necrosis (RTN)
Poor or declining polyp extension
Visible disease or pests
Significant tissue damage
Been exposed to major parameter changes

Healthy colonies generally have a much better ability to recover from physical damage than stressed colonies. The goal of sustainable coral fragging isn't to get as many pieces as possible from a coral. It's to produce healthy frags while keeping the parent colony healthy enough to continue growing.

Equipment You'll Need

Before making your first cut, prepare your entire workspace so the coral spends as little time out of the aquarium as possible. This is extraordinarily important for Acropora because of their general sensitivity.

Recommended equipment includes:

Coral or bone cutters
Container filled with aquarium water
Frag plugs or frag rock
Reef-safe cyanoacrylate gel
Paper towels
Gloves
Eye protection
Clean cutting surface

A coral saw can also be useful for unusually thick branches or colonies with growth patterns that aren't well suited to bone cutters.

Bone Cutters vs. Coral Saws

Bone cutters are generally the simplest option for branching Acropora. They're fast, easy to use, and allow you to remove individual branches with a single cut.

Coral saws provide more control when working with thicker branches or unusual colony structures where a bone cutter could crush or fracture the skeleton. For routine propagation of healthy branching Acropora, bone cutters are usually sufficient.

Having your workspace completely prepared before removing the coral makes the process faster and reduces unnecessary handling.

How to Frag Acropora

Step 1 — Prepare Your Workspace

Before removing the Acropora, turn off circulation pumps and wavemakers. Prepare a shallow container using water from your display aquarium. This gives you a working environment that matches the coral's existing temperature and salinity.

Lay out your cutters, frag plugs, glue, paper towels, and any other tools before removing the coral. If you're able to remove the colony or rock from the aquarium without disturbing your aquascape unnecessarily, place it in the prepared container.

The goal is simple: Have everything ready before the coral leaves the tank.

Step 2 — Select and Remove the Branch

Choose a healthy branch with good tissue coverage and visible growth. Look for a section that can be removed without compromising the structure of the parent colony. Consider the shape the colony will have after the cut. A well-placed fragging cut can encourage the remaining colony to continue growing naturally while producing a useful new frag.

Avoid cutting through:

Receding tissue
Damaged areas
Dead or exposed skeleton unless intentionally removing damaged material
Areas showing signs of disease

For branching Acropora, position your cutters around the branch at the point where you want the new frag to separate.

Step 3 — Cut the Acropora

Make a clean, decisive cut through the branch. The goal is to separate the frag without unnecessarily crushing or fracturing the skeleton.

Avoid repeatedly squeezing the cutters or trying to slowly crush through a branch. A sharp tool and a deliberate cut generally produce a cleaner result. The new frag should contain healthy living tissue along the portion of skeleton that remains attached to it. Likewise, leave enough healthy structure on the mother colony for it to continue growing.

Don't maximize the number of frags.

It's tempting to look at a large Acropora colony and wonder how many pieces you can get from it. Resist that temptation. Larger, healthy frags generally have more tissue and stored resources available for recovery than extremely small pieces, and the parent colony needs enough healthy structure to continue growing.

Sustainable fragging means propagating a coral without sacrificing the long-term health of the colony.

Step 4 — Mount the New Frag

Once the branch has been separated, prepare the mounting surface. Dry the portion of the frag plug where the Acropora will be attached and apply a small amount of reef-safe cyanoacrylate gel.

Position the base of the Acropora against the glue and hold it securely until the adhesive sets. Avoid covering living tissue with glue. The frag should be stable enough that it cannot easily fall over or be knocked loose by normal aquarium flow.

Once mounted, return the frag to aquarium water as quickly as practical. Acropora will eventually grow over the attachment point and encrust onto the substrate, creating a much stronger natural attachment.

Step 5 — Healing

Acropora can look noticeably different immediately after fragging. The coral may retract its polyps, produce additional mucus, or show temporary changes in coloration and appearance. This doesn't necessarily indicate a problem.

First 24 Hours

You may notice:

Reduced polyp extension
Mucus production
Retraction around the cut
Temporary changes in coloration

Keep the coral in stable conditions and avoid unnecessary handling.

First Week

The freshly cut area should begin stabilizing as the coral recovers from the physical damage.

Continue maintaining stable:

Temperature
Salinity
Alkalinity
Calcium
Magnesium
Nutrient levels

Avoid making major changes to lighting or flow simply because the coral has been fragged.

First Few Weeks

Healthy Acropora frags can begin developing new tissue around the cut and eventually start encrusting onto the frag plug.

Signs that recovery is progressing well include:

Stable tissue coverage
Returning polyp extension
Normal coloration
Encrustment around the base
Continued growth

Warning signs include:

Rapid tissue recession
Continued tissue loss
Severe or persistent discoloration
Deterioration spreading away from the original cut
Failure to stabilize after fragging

If a frag begins deteriorating, investigate the aquarium rather than repeatedly handling or relocating the coral.

Should You Feed Acropora After Fragging?

Acropora obtain much of their energy through photosynthesis, but they can also capture small particles and organisms from the water column. Freshly fragged Acropora generally don't need to be target-fed immediately after cutting.

The more important priorities during recovery are stable water chemistry, appropriate lighting, adequate flow, and avoiding unnecessary stress. Once the frag has recovered and resumed normal behavior, feeding can be incorporated into the aquarium's normal husbandry routine if desired. Avoid aggressively target-feeding freshly cut Acropora while the tissue around the cut is still recovering.

Common Acropora Fragging Mistakes

Many unsuccessful Acropora frags can be traced back to a handful of common mistakes.

These include:

Fragging an unhealthy colony
Fragging immediately after acquiring the coral
Using dull or inappropriate cutting tools
Crushing the branch instead of making a clean cut
Cutting through damaged or receding tissue
Attempting to maximize the number of frags
Handling the fresh frag repeatedly
Covering living tissue with glue
Poorly securing the frag to its substrate
Exposing a fresh cut to excessive direct flow
Dramatically changing lighting after fragging
Allowing water parameters to fluctuate during recovery
Moving the frag repeatedly because it doesn't immediately look healthy

The easiest way to improve Acropora fragging success is to remember that the cutting itself is only one part of the process. A clean cut followed by poor recovery conditions can still result in a failed frag.

Water Parameters for Newly Fragged Acropora Corals

Freshly fragged Acropora don't require a special set of water parameters simply because they've been cut. Instead, maintain the stable reef conditions the parent colony was already accustomed to.

Parameter

Recommended Range

Why It Matters

Temperature

76–80°F (24.5–27°C)

Stable temperature reduces stress during recovery.

Salinity

1.025–1.026 SG (35 ppt)

Maintaining natural seawater salinity promotes healthy tissue repair and minimizes osmotic stress after fragging.

Alkalinity

7–10 dKH

Stable alkalinity supports skeletal growth and recovery as the Acropora rebuilds its skeleton around the cut to resume encrustation. Consistency is generally more important than the exact value.

Calcium

400–450 ppm

Calcium is required for new skeletal growth as the Acropora heals and begins rebuilding around the cut and growing new tissue.

Magnesium

1280–1400 ppm

Magnesium helps maintain stable calcium and alkalinity while supporting healthy skeletal growth and calcification.

Nitrate

2–15 ppm (Detectable)

Measurable nitrate supports coral metabolism and tissue recovery. Avoid extremely low nutrients during recovery, while excessive nutrients can encourage nuisance algae.

PAR

Species/colony dependent

Acropora corals are relatively species-dependent in terms of their PAR preferences, although stability is always important. Avoid sudden increases in light after fragging while the coral recovers.

Phosphate

0.03–0.10 ppm (Detectable)

Maintaining measurable phosphate supports coral metabolism without requiring an ultra-low-nutrient environment. Avoid excessive nutrients that can encourage nuisance algae.

Water Flow

Strong, turbulent, indirect

Strong, varied flow helps deliver oxygen and nutrients while removing waste and mucus from freshly cut tissue. Avoid direct flow that can keep the coral retracted or disturb the fresh cut.

The most important part of this table is stability.

Don't start chasing numbers because you just fragged your Acropora. Large or rapid changes in water chemistry can create additional stress during a period when the coral is already recovering from physical damage.

Frequently Asked Questions

Can you frag Acropora with bone cutters?

Yes. Bone cutters are one of the simplest tools for fragging branching Acropora. They allow you to make a quick, controlled cut through individual branches without stressing other parts of the colony.

Can you frag Acropora with a coral saw?

Yes. A coral saw can be useful for thicker branches, unusual growth forms, or situations where a more controlled cut is desirable. The use of a coral saw generally requires a bit more control and is recommended only for fragging sections of a colony that are too thick for bone cutters.

How big should an Acropora frag be?

There isn't one ideal size for every Acropora. Larger frags generally have more tissue and skeleton available for recovery, while smaller frags can be propagated successfully when taken from a healthy colony and provided with appropriate conditions. The goal of fragging is typically to create fragments that are capable of healthy recovery, so sustainable long-term fragging is often focused more on recovery timelines than frag count per session.

Where should you cut an Acropora?

For branching Acropora, select a healthy section of branch with good tissue coverage and make a clean cut through healthy skeleton. Avoid damaged or receding areas whenever possible. Other growth patterns may require different techniques for fragging, but the general rule is to follow natural growth divisions and separate colonies at those divisions whenever possible.

Can you frag Acropora underwater?

Yes. Fragging Acropora in a container of aquarium water is a practical way to keep the coral submerged during the process and minimize unnecessary environmental changes. This is generally recommended if the colony can be easily removed from the aquarium.

How long does an Acropora frag take to recover?

Recovery varies between corals and aquarium conditions. A healthy frag may begin stabilizing within days, while visible encrustment and new growth can take several weeks or longer. Leaving more skeleton attached to each frag provides more tissue to support recovery after fragging, so fragging larger pieces may help if you are interested in improving recovery rates.

Should you dip Acropora after fragging?

Fragging itself does not automatically require a coral dip. If you use a coral dip as part of your normal pest-prevention or quarantine process, follow the product's directions and avoid unnecessarily stressing freshly cut tissue. Contrary to popular opinion, using unnecessary dips can actually increase stress levels and cause more harm than good during fragging, so it’s recommended to conduct research on the specific product in question.

How often can you frag Acropora?

There is no universal schedule. A healthy Acropora can be fragged again after the parent colony has fully recovered and demonstrated continued growth. Sustainable propagation is based on the health and growth of the colony rather than a fixed calendar.

Can you frag encrusting Acropora?

Yes, but encrusting Acropora can require a different approach than branching varieties. Instead of simply removing a branch, propagation may involve cutting a portion of the encrusted colony or substrate. The specific technique depends heavily on how the coral has grown.

Is Acropora difficult to frag?

The physical cutting process is relatively straightforward with a healthy branching colony. The more difficult part is maintaining the stable aquarium conditions Acropora require before and after fragging.

Can beginners frag Acropora?

Acropora is generally considered an advanced coral, so it isn't usually the first coral we'd recommend learning to frag. Once an aquarist has an established, healthy Acropora colony, however, the basic propagation process is relatively straightforward. People with very mature aquaria may find that the most difficult part of fragging Acropora is actually quite manageable in their tanks, in which case this can be a fantastic option to practice fragging branching stony corals on. People with younger tanks, on the other hand, may find that there are other corals like duncan or candy canes that may be more immediately accessible candidates for learning to frag with this technique.

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