Sand Sifting Starfish

Sand Sifting Starfish: Helpful Cleaner or Risky Addition?

Sand Sifting Starfish are often sold as the perfect clean-up crew member for saltwater aquariums. They glide under the sand, turning it over and keeping it looking bright and fresh. But before you add one to your reef tank, it’s important to understand their care needs and potential downsides.

What Do Sand Sifting Starfish Eat?

Despite their reputation as simple sand cleaners, Sand Sifting Starfish are actually voracious predators of the tiny life within your substrate. They feed on:

  • Microfauna such as copepods and amphipods
  • Worms and other small invertebrates
  • Detritus and leftover food (to a lesser extent)

In a new or low-biodiversity tank, they often starve once they’ve consumed the available microfauna. These starfish are best suited for large, mature aquariums with deep, well-established sand beds full of life.

Rule of thumb: if you can’t see lots of life in your sand bed at night with a flashlight, your tank may not be ready for a Sand Sifting Starfish.

Care Requirements and Tank Size

Sand Sifting Starfish are relatively hardy once established, but they do have specific needs:

  • Tank size: At least 55 gallons; larger systems are strongly recommended.
  • Sand bed: 2–4 inches of fine to medium grain sand for burrowing.
  • Age of tank: 6–12 months old or more, with a mature biological community.
  • Stable parameters: Sensitive to swings in salinity, temperature, and alkalinity.

Always acclimate them slowly using a drip method, as sudden changes in salinity can be fatal.

Pros, Cons, and Alternatives

Before you buy a Sand Sifting Starfish, weigh the benefits and drawbacks for your specific setup.

Benefits

  • Helps keep the upper layers of sand turned and oxygenated
  • Can reduce visible detritus on the sand surface
  • Interesting burrowing behavior and unique appearance

Drawbacks

  • Can strip your sand bed of beneficial microfauna
  • Often slowly starves in smaller or newer tanks
  • Difficult to target feed consistently

If your main goal is a clean, white sand bed, consider alternative clean-up crew members that are easier to feed and more sustainable long-term, such as Nassarius snails or sand-sifting gobies.

For more guidance on building a balanced clean-up crew, check out our article on clean-up crew options for reef tanks. If you’re planning a new system, our guide to live sand vs. dry sand can help you start with a healthier substrate. And if you already keep these invertebrates, you may also be interested in our care tips for reef-safe starfish species.

In the right aquarium, with plenty of mature sand and microfauna, a Sand Sifting Starfish can be a fascinating addition. Just be sure your tank can truly support its long-term nutritional needs before bringing one home.