Blue Leg Hermit Crab
Tiny, electric-blue legs and an endless appetite for hair algae and detritus.
The workhorse hermit of the cleanup crew: small, reef safe, and relentless on hair algae, cyano, and detritus in the rockwork and sand. Its striking electric-blue banded legs make it easy to spot working the tank. Provide spare shells so it never turns to snail shells as it grows.
What it needs to thrive
- Lighting
- Any standard reef lighting — no special requirements.
- Flow
- Moderate reef flow with calm resting zones.
- Feeding
- Omnivorous scavenger — hair algae, detritus, leftover food, and seaweed sheets.
- Temperament
- Peaceful; keep stocked with spare shells.
- Difficulty
- Beginner
- Ideal Tank Size
- 5 gallons and up, fully cycled.
- Water Parameters
- 76–80°F · salinity 1.024–1.026 SG · pH 8.1–8.4 · 0 ammonia / 0 nitrite · nitrate under 10 ppm
Sand bed, rockwork, and glass — patrols every surface. Add 1 per 3–5 gallons for a strong crew.
Reef safe and peaceful at its small size. Offer empty shells to prevent disputes over homes.
Quarantine, dip, and acclimation
Quarantine
Hold all new fish in a bare-bottom 10–20 gallon QT for a minimum of 4 weeks. Observe for flashing, clamped fins, white spots, or breathing changes. Treat preventatively with copper (1.75–2.5 ppm chelated) or tank-transfer method for ich, plus a praziquantel course for flukes. Invertebrates and corals skip QT but go through dip and observation instead.
Recommended coral dip
For every new coral: a 5–10 minute bath in your reef-safe dip of choice (Bayer Complete, CoralRx, or Reef Primer) following label dosage, followed by two clean saltwater rinses. Inspect plugs and bases for flatworms, pyramid snails, and eggs — remove or refrag onto clean plugs before placing in display.
Acclimation
Float sealed bags in your QT or display for 15 minutes to match temperature. Then drip acclimate at 2–4 drops per second for 45–60 minutes until volume has tripled. Net livestock into the tank — never pour shipping water in. Dim the lights for the first 24 hours to reduce stress.