Clean Up Crew For Reef Tanks

Building a thriving reef tank isn’t just about colorful corals and fish. A well-chosen clean up crew (CUC) quietly handles leftover food, nuisance algae, and detritus so your system stays stable and beautiful. The right mix of snails, crabs, and other invertebrates can dramatically reduce maintenance and help prevent common problems like algae blooms and dirty sandbeds.

Why a Clean Up Crew Matters in Reef Tanks

A healthy reef aquarium relies on balance. Every time you feed your fish or add new livestock, you increase the system’s nutrient load. Without a clean up crew, uneaten food and waste break down into nitrate and phosphate, fueling algae and stressing corals.

A good CUC helps by:

• Controlling algae on glass, rocks, and the sandbed.
• Stirring the substrate to prevent dead spots and compacted sand.
• Consuming detritus before it decomposes and harms water quality.
• Supporting biodiversity, which improves overall tank stability.

If you’re still planning your system, be sure to read our guide on reef tank maintenance schedules so your CUC is part of an overall long-term plan.

Best Clean Up Crew Choices for Reef Aquariums

There is no single “perfect” crew for every tank. Instead, aim for a mix of species that target different areas: rockwork, glass, sand, and hidden crevices.

Snails: The Core of Most Clean Up Crews

• Trochus snails – Excellent for film algae on glass and rock. They can right themselves if flipped, making them hardy choices for beginners.
• Nassarius snails – Live in the sand and emerge when they sense food. Great for stirring the substrate and eating leftover meaty foods.
• Cerith snails – Small, versatile cleaners that graze on film algae, diatoms, and detritus in tight spaces.
• Turbo snails – Powerful algae eaters for larger systems; best used sparingly because of their size and bulldozer-like behavior.

Crabs, Shrimp, and Other Helpful Inverts

• Hermit crabs – Blue-leg and scarlet hermits help with algae and leftover food. Provide extra empty shells to reduce shell-related aggression.
• Cleaner shrimp – Skunk cleaners and similar species will scavenge food and may clean parasites off fish.
• Emerald crabs – Often used to help control bubble algae. Best kept well-fed and monitored in smaller tanks.
• Sand-sifting sea cucumbers – For mature, stable systems with fine sand, they can keep the substrate looking pristine.

Pro tip: Add your clean up crew gradually. Start with a modest number of snails and crabs, then increase only if you still see excess algae or detritus after a few weeks.

Stocking, Care, and Long-Term Success

Overstocking a CUC is a common mistake. If you add too many inverts at once, they can run out of natural food and slowly starve. A better approach is to stock based on your tank’s size and actual nutrient load.

• For a lightly stocked 20–40 gallon reef, start with 6–10 snails and a couple of small hermits.
• For a 75+ gallon system, build up to a diverse group of 20–30+ snails, a handful of hermits, and a few specialty inverts.

Remember that a clean up crew supports good husbandry; it doesn’t replace it. Strong export methods (protein skimming, water changes, and refugiums) and proper feeding are still essential. For a deeper dive into keeping nutrients in check, see our article on controlling nutrients in reef tanks.

Finally, research compatibility. Some fish, such as certain wrasses and puffers, may prey on snails and shrimp. Quarantining new additions and following a careful acclimation process (described in our saltwater fish acclimation guide) will also help your CUC survive long term.

With a thoughtfully chosen clean up crew and balanced stocking, your reef tank will stay cleaner, more stable, and more enjoyable to maintain. Over time, you’ll learn which species thrive in your particular system and can fine-tune your crew for a reef that looks vibrant and runs smoothly.

Sources

• Borneman, E. H. Aquarium Corals: Selection, Husbandry, and Natural History. TFH Publications.
• Fenner, R. The Conscientious Marine Aquarist. Microcosm.
• Sprung, J. & Delbeek, J. C. The Reef Aquarium series. Ricordea Publishing.
• General best practices compiled from long-term hobbyist experience and reef aquarium community consensus.