🦐 Aquarium Invertebrate Guide
Shrimp, snails, crabs, urchins, and more. Build the perfect cleanup crew or add ornamental inverts to your reef.
Building a Cleanup Crew
A cleanup crew (CUC) is essential for maintaining a healthy aquarium. Snails, hermit crabs, and shrimp eat algae, leftover food, and detritus that would otherwise foul your water. A well-stocked CUC dramatically reduces maintenance and keeps your tank looking clean.
How Many Snails Per Gallon?
A common starting point is 1 snail per 2-3 gallons for reef tanks. For a 75-gallon reef, that's roughly 25-35 snails of mixed species. Use a variety: Trochus and Astrea for glass algae, Nassarius for sand stirring, Cerith for detritus. Add 1 hermit crab per 5 gallons (10-15 for a 75-gallon tank).
Avoid overstocking your CUC — if there isn't enough algae to sustain them, they'll starve. Start with half the recommended amount and add more as needed. Certain invertebrates like emerald crabs and peppermint shrimp also target specific pest algae and aiptasia.
Related Tools
Check compatibility before adding inverts: Compatibility Checker | Fish Guide | Tank Volume Calculator