Sand sifting starfish reef compatibility check
Astropecten polycanthus
Sand sifting starfish (Astropecten polycanthus) is an expert-level starfish that needs at least 100 gallons. It is reef safe with caution; often starves in small or young sandbeds. Temperament varies and adults reach about 8 inches. Add it as middle-stage livestock once the tank is at least 9 months old.
Commonly sold but frequently inappropriate for young starter reefs.
Who it is for
Good fit for
- ✓ Tanks of 100+ gallons at the animal's adult size.
Not a fit for
- ✕ Tanks under 100 gallons, even while it is small.
- ✕ Keepers without experience and a long-stable system.
- ✕ New tanks; wait until the system is about 9+ months old.
- ✕ Reefs where the cautions on this page would put existing corals or inverts at risk.
Compatibility warnings
- Often starves in small or young sandbeds.
- Avoid for most beginner tanks.
- Check adult size against the final tank, not the fish or coral at purchase size.
- Add livestock slowly so the bioload and nutrient export can keep up.
- Use the planner when this animal changes the tank-size, flow, lighting, or stocking plan.
Professional planning context
- Use the 100 gallon minimum as an adult-planning floor; display length, aquascape, and existing tankmates can raise that floor.
- Hold this entry until the system has at least 9 months of maturity or equivalent stability evidence.
- Invert plans should account for copper exposure, acclimation sensitivity, predation risk, and whether the tank can actually feed the animal.
Tank fit and maturity gate
ReefCrafter uses 100 gallons as the planning floor for adult size, swimming room, nutrient load, and aggression margin.
This animal should wait until the tank has enough age, food web stability, or parameter history.
Care notes
- Temperament
- Varied
- Reef safety
- Caution
- Adult size
- 8 in
- Placement
- Build dependent
- Diet
- Build dependent
- Flow
- Varied
- Light
- None
- Bioload
- 0.6
- Stocking stage
- Middle
Related species
- Serpent starfish
50+ gallons, intermediate care.
- Derasa clam
75+ gallons, intermediate care, high light, reef safe.
- Maxima clam
50+ gallons, high light, reef safe.
- Pincushion urchin
40+ gallons, intermediate care.
Equipment that fits
- Waterbox REEF 220.6 Aquarium System (167 gallons)
167-gallon display, above this animal's 100-gallon floor.
- Red Sea Reefer Peninsula 500 G2+ Aquarium System (109 Gal)
109-gallon display, above this animal's 100-gallon floor.
- CADE Pro Reef 900 Series 2
110-gallon display, above this animal's 100-gallon floor.
Related reading
Questions
What size tank does the sand sifting starfish need?
ReefCrafter plans for at least 100 gallons, based on an adult size of about 8 inches, plus room to forage and the stability a larger water volume gives. Use the adult size, not the size at purchase.
Is the sand sifting starfish reef safe?
It is reef safe with caution in ReefCrafter's catalog. Watch for: Often starves in small or young sandbeds; Avoid for most beginner tanks.
Is the sand sifting starfish good for beginners?
It is rated expert care, so most beginners should add it later, after parameters have been stable for 9+ months.
When should I add the sand sifting starfish to my tank?
ReefCrafter treats it as middle-stage livestock for a tank at least 9 months old. Add livestock slowly so nutrient export keeps up.