𝐑𝐞𝐞𝐟-𝐒𝐚𝐟𝐞, 𝐒𝐚𝐧𝐝-𝐒𝐭𝐢𝐫𝐫𝐢𝐧𝐠, 𝐚𝐧𝐝 𝐒𝐞𝐫𝐢𝐨𝐮𝐬𝐥𝐲 𝐂𝐨𝐨𝐥:
𝐌𝐞𝐞𝐭 𝐭𝐡𝐞 𝐂𝐨𝐧𝐜𝐡𝐬

Introduction

When it comes to sand-sifting cleanup crews, most people think of nassarius snails or sand-sifting gobies. But lurking just under the surface—literally—is one of the most underrated and fascinating members of the reef aquarium cleanup team: the conch. With their quirky “elephant trunk” siphons, bulldozer-like shells, and relentless appetite for detritus and algae, conchs are equal parts functional and fun to watch.

You all know that I love weird, incredible, and entertaining invertebrates for my tanks. So in this article, I want to introduce you to the wonder world of conchs with the goal of having you fall in love with them! This article dives into the biology, care, and benefits of conchs in reef tanks, as well as some of my pro tips to keep them thriving and your sandbed pristine.

What Exactly Is a Conch?

Conchs are marine gastropods (snails) known for their distinctive spiral shells, elephant-like siphons, and unique way of moving. Unlike many snails that glide, conchs use their muscular foot and operculum like a spring to “hop” across the substrate. In reef aquariums, they’re prized for their ability to keep sandbeds clean and oxygenated by grazing on detritus, diatoms, and film algae.

Conchs are primarily sand-dwelling, spending most of their time on or just beneath the substrate. Their long proboscis allows them to vacuum food particles from the surface, making them natural sandbed janitors. They’re peaceful, reef-safe, and one of the few invertebrates that combine utility with quirky behavior, earning them a spot in many cleanup crews.

Popular Conch Species for Reef Aquariums

1. Fighting Conch (Strombus spp.)

Size: 2–4 inches (5–10.16 cm)

Tank Size: 30 gallons or larger with at least 1–2 inches of sandbed

Unique Traits:

The Fighting Conch is the classic go-to for saltwater hobbyists who want a reliable, efficient sandbed janitor. Don’t let the name fool you—they’re peaceful and mild-mannered in aquariums. The “fighting” part comes from their natural behavior in the wild where males may jostle for mates or food access. In your tank? They’re just trying to mind their own (algae-grazing) business.

Their elongated, thick shell is usually brown to orange with subtle purple or cream streaks, and they use their muscular foot and operculum like a pogo stick to hop awkwardly—but effectively—across the sand. It’s oddly endearing to watch.

2. Strawberry/ Tiger Conch (Conomurex luhuanus)

Size: 2–3 inches (5–7.5 cm)

Tank Size: 30 gallons or larger.

Unique Traits:

Often overlooked but absolutely stunning, the Strawberry or Tiger Sand Conch brings a bit of flair to your sandbed game. Named for their bold, patterned shells, these conchs range from speckled reds (hence “strawberry”) to striped browns and creams (earning the “tiger” nickname). While the specific taxonomy can vary depending on region and source—most of what’s sold in the hobby comes from Strombus species complexes in the Indo-Pacific—they generally behave like smaller, flashier versions of the Fighting Conch.

Their movement is particularly entertaining. These little sand-skaters “hop” around using their powerful foot and operculum like a spring. You’ll see them lurch forward, bury themselves halfway, or pivot to graze in slow-motion spirals. It’s not only useful—it’s fun to watch.

3. Queen Conch (Lobatus gigas)

Size: Up to 12 inches (30 cm) as an adult.

Tank Size: Not recommended for most home aquariums due to their massive adult size and food requirements. Also, protected in many areas such as Florida and the Bahamas due to over harvesting.

Unique Traits:

The Queen Conch is the stuff of legends—and snorkeler selfies. Native to Caribbean seagrass beds, this species is instantly recognizable by its massive, flared shell, often pink or peach on the inside, and a thick outer lip that develops with age. In the wild, they play a crucial role in nutrient cycling and algae control, grazing on seagrass and biofilm while aerating the sediment.

As juveniles, they’re sometimes sold into the aquarium trade under 2–3 inches, but this is where the problem starts: they don’t stay small for long. With proper diet and water quality, they can double in size within a year—and most home tanks aren’t ready for a creature that rivals a football in length (and appetite).

4. Spider Conch (Lambis sp.)

Size: 6–12 inches (15–30 cm)

Tank Size: 125 gallons or more

Unique Traits:

With long, curved spines extending from the outer lip of their shells, these inverts look like something out of a sci-fi flick—yet they’re completely reef-safe and surprisingly gentle. Their shell shape helps camouflage them among reef rubble in the wild, and those dramatic spines also deter predators. The issues I typically see with these conchs is that they knock over rocks and corals due to their large size. They definitely need to be in very large tanks with plenty of room to maneuver around. 

Species commonly seen in the trade (like Lambis lambis and Lambis truncata) are native to the Indo-Pacific and are true visual stunners. That said, they’re not common in the hobby, largely due to their size and the challenges in sourcing them sustainably. But when they do show up, they attract attention fast. They tend to do better in rubble zones rather than true sand.

5. Hawkwing Conch (Strombus raninus) - Rare in the hobby

Size: 2.5–4 inches (6–10 cm)

Tank Size: 30 gallons or larger

Unique Traits:

The Hawkwing Conch is a true underdog in the hobby—often overlooked, but absolutely worth your attention. It gets its name from the distinctive, wing-like flares on its outer shell, giving it a bold, architectural look that’s equal parts gothic cathedral and sea creature. The shell is typically thick and sculpted, often showing earth-toned browns and oranges with subtle striations. The body itself is mottled and well-camouflaged for sandy or rubble zones.

Like its close relatives, the Hawkwing uses a powerful, spring-loaded foot and operculum to “hop” forward in short, slow-motion bursts. It’s not the most graceful movement in the tank, but it’s definitely fun to watch—and surprisingly efficient for traversing sandbeds.

Why Keep Conchs in Your Aquarium?

1. Sandbed Cleaning Powerhouses

Conchs are the Roombas of the reef, but way more interesting to watch. They spend their days grazing on:

•Diatoms, Film algae, Uneaten food, Decaying organic matter

By constantly vacuuming the upper layers of your substrate, they help prevent nutrient spikes that can fuel nuisance algae or cyanobacteria blooms. Think of them as slow-motion janitors with a lifelong mission to keep your sand pristine.

2. Aerating the Substrate

Beyond surface-level cleaning, conchs gently stir and oxygenate the sandbed. Their movement:

•Helps avoid anaerobic “dead zones”

•Prevents dangerous gases like hydrogen sulfide from accumulating

•Encourages healthy bacterial populations to thrive

Unlike sand-sifting stars, which can decimate your microfauna, conchs don’t dig too deep or disturb beneficial critters. It’s a soft, sustainable kind of aeration—perfect for tanks with live sand.

3. Low Risk to Corals and Inverts

One of the biggest headaches in reefkeeping is finding clean-up crew members that won’t go rogue. Some crabs get nippy. Some starfish go on coral walks. But conchs? They’re model citizens.

•100% detritivores and film algae grazers

•Will not nip at LPS or soft corals

•Ignore shrimp, snails, and most sessile inverts entirely

This makes them ideal for peaceful reef systems where frag placement, coral growth, and invert diversity are top priorities.

4. Endless Entertainment Value

Let’s be honest—snails aren’t usually known for charisma. But conchs? These guys are the exception.

•Their eyes pop up on stalks and swivel independently—like submarine periscopes. Seriously, they most adorable thing you will ever see!

•They move with an awkward “hop and drag” gait that’s half pogo stick, half stumbling forward.

•Occasionally, you’ll catch them doing a full shell flip if they tip over—an acrobatic feat for any mollusk.

Conchs add an unexpected level of personality to your tank. Watching them crawl over algae patches, bury themselves in the sand, or curiously inspect tank mates makes them oddly engaging—even relaxing—to observe.

Tank Requirements

Before you add one of these charismatic grazers to your reef system, make sure their basic housing needs are met. While conchs are hardy and adaptable once settled, they’re still sensitive to poor substrates and unstable parameters—especially if your system is on the smaller side.

Tank Size:

Fighting and Tiger Sand Conchs are excellent for tanks 30 gallons and up, provided there’s ample space for foraging. You’ll want at least 1–2 inches (most species do better with 3-4 inches) of sandbed depth, ideally spread across several square feet. These guys spend 90% of their time moving across or just under the sand surface—so tight quarters can lead to stress, food shortages, and even injury.

Tamara’s Pro Tip: For tanks under 40 gallons, stick to one conch max unless your sandbed is absolutely packed with algae and detritus. Overcrowding = underfed conchs.

Substrate Selection:

•Best Choice: Fine to medium-grain aragonite sand

•Avoid: Coarse crushed coral or jagged gravel

Why? Conchs use a soft, muscular foot to crawl and burrow. Coarse or sharp substrate can tear or irritate that foot, which not only slows them down but compromises their feeding behavior and overall health. Smooth, compactable sand also allows them to burrow when resting or avoiding light.

Parameters:

• Temperature: 75–80°F (24–27°C)
  
  
• Salinity: 1.024–1.026
  
  
• pH: 8.1–8.4
  
  
• Alkalinity: Stable, within reef-safe ranges
  

Acclimation Sensitivity

Conchs are highly sensitive to rapid parameter shifts. Poor acclimation can lead to shock or death.

Proper Acclimation Steps:

1. Drip Acclimate (2+ Hours) – Use airline tubing with a knot to adjust flow to 1–2 drips per second.

2. Match Temperature First – Float the bag in the tank for 20 minutes to equalize temp.

3. Test Bag vs. Tank Salinity – If salinity differs by >0.002, extend acclimation to 3+ hours.

4. Avoid Sudden pH Swings – Conchs prefer stable pH (8.1–8.4). Acclimate during daylight hours when pH is highest.

Signs of Acclimation Stress:

• Retracted siphon for >24 hours.

• Failure to move or bury within 12 hours of introduction.

• Excessive mucus production.

Behavior and Daily Life

Conchs spend most of their time scouring the sand surface, occasionally burying themselves during rest or when startled. Their long siphon acts like both a food vacuum and a sensory organ, probing the sand ahead of them.

Unlike nassarius snails, conchs don’t typically dive deep into the substrate. Instead, they focus on the top layer where detritus and algae accumulate.

Feeding Conchs

In well-established tanks, conchs often find enough natural food to sustain themselves. However, in newer or ultra-clean systems, supplemental feeding is essential.

Diet: Film algae, diatoms, detritus, and leftover food.

Supplemental Feeding: conchs primarily need benthic microalgae and detritus. 

• Spirulina pellets

• Live phytoplankton (for biofilm growth)

• Commercial invert foods (e.g., Ocean Nutrition’s "Invert Feast")

Tamara's Pro Tip: If you notice your conch climbing glass or rocks frequently, it’s often a sign that food on the sandbed is running low.

Tankmates: Friends and Foes

Compatibility:

Conchs are ideal for peaceful reef communities and pair well with:

•Reef-safe fish: Clownfish, gobies, blennies, firefish, cardinalfish

•Corals: All types—SPS, LPS, softies. Conchs don’t bother polyps or tissue.

•Other inverts: Cleaner shrimp, serpent stars, urchins, trochus and astrea snails

They’re completely non-aggressive and won’t nip, nip back, or outcompete most species. As long as they have enough sandbed to roam and graze, they’ll mind their own business.

Use Caution With:

Certain tankmates can pose serious risks to conchs, either by injuring them or starving them out:

•Large predatory fish like:

•Larger Wrasses (e.g. Melanurus, Harlequin Tusk)

•Triggerfish

•Pufferfish

These species may peck at the foot or operculum, or flip conchs to expose vulnerable tissue.

•Sand-sifting starfish can outcompete conchs by stripping beneficial microfauna and detritus from the substrate. This reduces the available food pool—especially in smaller tanks.

•High-density Nassarius snail populations are surprisingly competitive. They respond aggressively to feeding and can easily swarm food meant for conchs, limiting their intake.

Common Issues and Troubleshooting

1. Starvation: The most common cause of death. Ensure adequate food supply or supplement regularly.

2. Flipped Over: Conchs can right themselves most of the time, but in tanks with sharp rockwork, check occasionally and assist if stuck.

3. Too Many Conchs: Overcrowding leads to food shortages. One Fighting Conch per 30–40 gallons is a good rule of thumb.

4. Retract for days: Some Conchs will "play dead" when first acclimated to a tank if they are stressed. Make sure to give your conch some time to acclimate.

Signs Your Conch Is in Trouble

1. It’s Spending More Time on Rock or Glass Than the Sandbed

• What It Means: The sandbed may be running out of food.
  
  
• Action: Supplement with sinking pellets or algae wafers. Long-term, evaluate if the tank can support a conch’s feeding needs.
  
  

2. The Sandbed Looks Spotless and White

• What It Means: The conch has done its job a little too well and may be running out of detritus and film algae.
  
  
• Action: Target feed small amounts of food on the sand to keep it sustained.
  
  

3. It’s Inactive or Spending Long Periods Buried

• What It Means: Could indicate starvation, stress, or declining health. Short rest periods under the sand are normal, but prolonged inactivity is a red flag.
  
  
• Action: Check water parameters and provide supplemental food.
  
  

4. It’s Losing Weight or the Shell Opening Looks Hollow

• What It Means:

Shrinking Foot Muscle – A healthy conch has a thick, muscular foot. If it appears thin or weak, the conch is malnourished.

Hollow or "Gaping" Shell Opening – The body retracts deeply, leaving an empty-looking space at the shell’s entrance.

• Action: 
  

Supplement with Benthic Foods – Offer spirulina pellets, sinking algae wafers, or live phytoplankton to boost biofilm growth.

Reduce Competition – Avoid overstocking sand-sifting species (e.g., nassarius snails, gobies).

Assess Tank Maturity – New tanks lack natural detritus. Wait 6+ months before adding a conch.

5. It’s Flipped Over and Can’t Right Itself

• What It Means: May be weakened, stressed, or stuck on uneven rock. Healthy conchs can usually right themselves quickly.
  
  
• Action: Gently flip it back onto the sandbed and monitor for repeated flipping. If it keeps happening, check for predators or flow issues.
  
  

6. The Siphon Is Rarely Extended

• What It Means: A healthy conch constantly uses its trunk-like siphon to probe the sand. A retracted siphon can indicate stress or illness.
  
  
• Action: Test water parameters, ensure stable conditions, and observe feeding response.
  
  

7. Shell Damage or Cracks

• What It Means: Can result from rough rockwork, predator attacks, or calcium deficiency in the water.
  
  
• Action: Maintain proper calcium and alkalinity levels for shell health. Protect from aggressive tankmates.
  
  

8. The conch moves erratically or frequently closes its operculum (trapdoor)

• What it Means: Conchs can host unwanted stowaways, the most common being Pea Crabs (tiny, soft-bodied crabs) that live symbiotically, but stress the conch by stealing food.
• Action: Inspect the conch’s mantle cavity. Remove crabs gently with tweezers if found.

9. Shell Deterioration

A degrading shell indicates poor water quality or calcium deficiency.

Causes & Fixes:

• Low Calcium/Alkalinity – Maintain Ca (420–450 ppm) and Alk (8–10 dKH) for healthy shell growth.

• Abrasive Substrate – Replace sharp crushed coral with fine aragonite sand.

• Predator Damage – Keep conchs away from aggressive fish (e.g., triggers, large wrasses).

Conch FAQ

1. Q: How long do conchs live in a reef tank?

A: Most Fighting and Tiger Sand Conchs live around 5 years in captivity if provided with a steady food source and stable water parameters. Queen and Spider Conchs can live well over a decade in the wild but rarely reach full lifespan in home aquariums due to size constraints. Unfortunately, many die within 1-2 years due to starvation. 

2. Q: Are conchs nocturnal or diurnal?

A: They’re opportunistic and active both day and night, but you might see increased activity at night when there’s less fish traffic and more detritus available.

3. Q: Do conchs help with cyanobacteria or dinoflagellates?

A: They won’t touch cyanobacteria mats or toxic dinos. They’re effective against diatoms and harmless film algae but not a solution for problematic blooms.

4. Q: Can I mix a conch with sand-sifting gobies or other sand cleaners?

A: Yes, but be cautious in smaller tanks. Too many sand sifters competing for the same detritus can starve a conch quickly.

5. Q: How can I tell if my conch is healthy?

A: A healthy conch is active, constantly feeding, and has a firm grip on the substrate with its foot. The siphon should be extended regularly while foraging. A conch that stays retracted, loses weight, or fails to right itself when flipped may be stressed or starving.

Conch Myths & Facts

Myth #1: Conchs will clean every type of algae in your tank.

Fact: Conchs specialize in detritus, diatoms, and harmless film algae on the sandbed. They won’t eat hair algae, cyanobacteria, or dinoflagellates. Think of them as sand janitors, not full-service algae removers.

Myth #2: Conchs can live in bare-bottom tanks.

Fact: Conchs require a sandbed to survive. They rely on it for food, movement, and protection. Without sand, they quickly starve and can injure their foot trying to move on bare glass.

Myth #3: You can keep as many conchs as you want if your tank is large.

Fact: Even in large systems, conchs can outstrip the sandbed’s food supply if overstocked. One Fighting or Tiger Conch per 30–40 gallons is a safe ratio unless you supplement feed heavily.

Myth #4: Conchs will eat corals or other invertebrates if they get hungry.

Fact: Conchs are strict detritivores and algae grazers. They do not consume corals, polyps, or other inverts. If they’re constantly climbing onto corals, it’s usually a sign they’re searching for food, not eating the coral itself.

Conclusion

Conchs are the unsung heroes of the reef tank, combining utility and personality in a single package. They keep your sandbed clean, help maintain healthy substrate conditions, and provide endless entertainment with their quirky movement and curious behavior.

Whether you’re building a nano reef or managing a large mixed reef, a Fighting or Tiger Sand Conch can be the perfect addition to your cleanup crew. Treat them well, feed them when needed, and you’ll have one of the most effective (and charming) janitors in the ocean right in your tank.

Happy Reefing!

References:

1. Fenner, Robert M. The Conscientious Marine Aquarist: A Commonsense Handbook for Successful Saltwater Hobbyists. 2nd ed., Microcosm/T.F.H., 2008.

2. Sprung, Julian, and Charles Delbeek. The Reef Aquarium: A Comprehensive Guide to the Identification and Care of Tropical Marine Invertebrates. Vol. 3, Ricordea Publishing, 2005.

3. Calfo, Anthony, and Robert Fenner. Reef Invertebrates: An Essential Guide to Selection, Care, and Compatibility. Reading Trees Publications, 2001.

4. Shimek, Ronald L. *Marine Invertebrates: 500+ Essential-to-Know Aquarium Species.* Microcosm/T.F.H., 2004.