The Core: The Three Foods Every Hermit Crab Should Always Have

Most of your hermit crab’s food changes from day to day. The Core doesn’t.

The Core is Green Sand, Worm Castings, and Calcium. Keep all three available at all times, no matter what else you’re feeding.

Think of it as the foundation underneath the Buffet. It stays put while everything else rotates.

In This Guide
By the end of this article you'll know:
  • What The Core is
  • Why Green Sand matters
  • Why Worm Castings matter
  • Why Calcium is essential
  • How to offer The Core
  • How The Core fits into the Buffet Method

Green Sand

Green Sand provides trace minerals that may not be present in the foods offered that day.

Worm Castings

Worm Castings are nutrient-rich material created as worms break down organic matter.

Hermit crabs naturally forage through soil, leaf litter, and decomposing material in the wild.

Calcium

Calcium plays an important role throughout the molt cycle as hermit crabs shed and rebuild their exoskeleton.

Offer a single calcium source or a mix, like Calcium Reserve. Individual options include Crushed Crab & Lobster Shell, Oyster Shell Flour, Cuttlebone, Eggshell, and Coral Calcium.

Tip

You don’t need several separate calcium dishes. A mix like Calcium Reserve gives your crabs a few different sources and textures to pick through in one place.

How to Offer The Core

Green Sand, Worm Castings, and Calcium can be offered separately or mixed together.

I usually offer them separately, either in sections of the same dish or in a trio dish.

How The Core Fits Into the Buffet Method

The Core is the staple of the Buffet Method. It doesn’t change from day to day. Green Sand, Worm Castings, and Calcium are always there, while Complete Meals and Single Ingredients rotate around them.

Common Mistake

Changing the calcium source is fine. Removing calcium altogether isn’t. Rotate between sources, or use a mix like Calcium Reserve, but never let the dish sit empty.

Key Takeaway

Green Sand + Worm Castings + Calcium = The Core.

Keep all three available and let the rest of the Buffet do the rotating.

Sources & Further Reading
The Crab Street Journal
Land Hermit Crab Owners Society