CUC FAQ - Clean-Up Crew Guide

CUC FAQ - Your Complete Clean-Up Crew Guide

What is a CUC and why do I need one?

CUC stands for Clean-Up Crew - a collection of invertebrates including snails, hermit crabs, and other beneficial organisms that help maintain a healthy reef aquarium. They consume algae, detritus, leftover food, and other organic waste, acting as your tank's natural cleaning service. A good CUC is essential for maintaining water quality and preventing algae outbreaks.

How many CUC members do I need for my tank size?

As a general guideline:

  • Nano tanks (10-20 gallons): 5-10 members
  • Small tanks (20-40 gallons): 10-20 members
  • Medium tanks (40-75 gallons): 20-40 members
  • Large tanks (75+ gallons): 40+ members

Start with fewer members and add more based on your tank's needs. It's better to add gradually than overstock.

Which CUC species are best for different types of algae?

  • Hair algae: Emerald crabs, sea hares, and certain hermit crabs
  • Film/diatom algae: Cerith snails, Nassarius snails, and Trochus snails
  • Green algae on glass: Nerite snails, Astrea snails, and Turbo snails
  • Cyanobacteria: Cerith snails and certain sea cucumbers
  • Detritus: Nassarius snails, fighting conch, and sea cucumbers

Are CUCs reef-safe with corals and fish?

Most CUC members are completely reef-safe and won't harm corals or fish. However, some considerations:

  • Hermit crabs may occasionally knock over small coral frags
  • Large snails like Turbos can bulldoze through the tank
  • Emerald crabs may nip at corals if not well-fed
  • Always research specific species before adding to your tank

How do I acclimate CUC members?

Proper acclimation is crucial for CUC survival:

  1. Float the bag in your tank for 15-20 minutes to temperature acclimate
  2. Use the drip acclimation method for at least 30-60 minutes
  3. Snails and invertebrates are very sensitive to salinity and pH changes
  4. Never expose them to air - keep them submerged during transfer
  5. Add them to your tank during lights-off period to reduce stress

What do I feed my CUC if there's not enough algae?

If your tank is very clean, supplement their diet with:

  • Algae wafers or sheets (nori)
  • Blanched vegetables (zucchini, spinach)
  • Small pieces of frozen foods
  • Specialized invertebrate foods

Monitor your CUC - if snails are falling off glass or moving slowly, they may need supplemental feeding.

Can different CUC species live together?

Yes! In fact, a diverse CUC is recommended because different species target different types of waste and algae. A balanced crew might include:

  • Sand-sifting species (Nassarius snails, fighting conch)
  • Rock-grazing species (Trochus, Astrea, Cerith snails)
  • Glass cleaners (Nerite snails)
  • Detritus eaters (hermit crabs, sea cucumbers)

How long do CUC members typically live?

Lifespan varies by species:

  • Snails: 1-3 years on average
  • Hermit crabs: 2-4 years
  • Sea cucumbers: 5-10 years with proper care
  • Emerald crabs: 2-4 years

Proper acclimation, stable water parameters, and adequate food significantly impact longevity.

Common Mistakes to Avoid

  • Adding CUC too early - wait until your tank is fully cycled
  • Poor acclimation - take your time with drip acclimation
  • Overstocking - start small and add more as needed
  • Neglecting copper testing - copper is lethal to invertebrates
  • Expecting instant results - CUC works gradually over time

Ready to Build Your Clean-Up Crew?

Shop our CUC collection to find the perfect clean-up crew members for your reef tank. All our CUC species are hand-selected and properly quarantined to ensure they arrive healthy and ready to work!

Have more questions? Contact us - we're here to help you build the perfect clean-up crew for your reef!