How To Care For Sea Urchins

Essential Tips for Sea Urchin Care

Sea urchins are fascinating and beneficial additions to saltwater reef aquariums. Known for their unique appearance and utility as natural algae eaters, these spiny creatures contribute to a balanced ecosystem while adding visual intrigue. With proper care and a well-maintained habitat, they can thrive in your aquarium for years to come.

General Habitat & Tank Requirements:

Sea urchins are best suited for mature reef aquariums with stable water parameters and plenty of natural surfaces to explore. These echinoderms require specific environmental elements to thrive:

Tank Size: 20 gallons or larger for smaller species like Tuxedo Urchins. Larger Species like Long Spine Urchins will do better in 75+ gallon aquariums.
Aquascape: Include plenty of live rock to provide surfaces for grazing and hiding spots. Secure loose rocks to prevent them from being moved by the urchin's activity.
Substrate: While they have no specific substrate requirements, sand or fine gravel is ideal, as sea urchins can easily navigate and clean these surfaces.
Lighting: While urchins themselves don't have lighting requirements, it's usually best to keep them in environments with enough lighting to support some algae growth, which they will use as a food source.

Water Conditions:

Temperature: 75°F to 80°F (23°C to 27°C).
pH: 7.7 to 8.5.
Specific Gravity (Salinity): 1.023 to 1.026.
Water Quality: Maintain ammonia and nitrite levels at 0 ppm, and nitrates below 20 ppm.
Filtration: Employ high-quality filtration, such as a protein skimmer, to ensure optimal water quality.

Diet and Feeding

Sea urchins are primarily herbivores, feeding on algae that grow on rocks and aquarium surfaces.

Primary Diet: Macroalgae, coralline algae, and microalgae.

Supplementation: If natural algae levels are low, provide dried seaweed or algae wafers. Place supplemental food near them for easy access.

Behavior and Compatibility

Sea urchins are generally peaceful and compatible with most reef inhabitants, but there are some considerations to keep in mind:

Reef Safe: They are reef-safe but may inadvertently knock over unsecured corals and decor while grazing.

Tankmates: Avoid housing them with aggressive fish that may view them as food.

Activity: Most species are nocturnal and will be more active during the evening hours.

Health and Maintenance

To keep your clean up crew healthy and thriving, maintain excellent water quality through regular water changes of 10–25% every two to four weeks. Consistent testing of water parameters such as salinity, pH, ammonia, nitrite, and nitrate levels is essential to ensure a stable environment.

Monitor the condition of their spines, as loss or damage can indicate poor health, stress, or starvation.