Calcium carbonate powder is an essential supplement for many invertebrates, promoting strong shells and exoskeletons in species like snails, shrimp, and corals. It is widely available in pure powder form from various pet supply retailers.
 
Usage in Different Environments
Aquatic Invertebrates (Shrimp, Snails, Corals): Calcium carbonate is crucial in aquariums to stabilize the pH and maintain optimal general hardness (GH) and carbonate hardness (KH) levels.
Application: Powdered supplements can be mixed with tank water before adding to the aquarium for even distribution, or added to the filter to provide a gradual, long-term release.
Terrestrial Invertebrates (Snails, Isopods, Millipedes, Crabs): For land-based invertebrates, calcium powder is typically offered as a direct food supplement or a standalone source.
Application: Simply sprinkle a small amount over their food (vegetables, live food) or place it in a separate shallow dish within their enclosure for them to consume as needed. 
 
Important Considerations
Vitamin D3: Many animals, including some reptiles and amphibians, require Vitamin D3 to absorb calcium effectively. However, most invertebrates do not require D3 supplementation through their diet. When purchasing a product, ensure you choose one appropriate for your specific invertebrate species (some products, like certain 
Swell Calcium Powder
 variants, come with D3, while pure calcium carbonate powders do not).
Water Chemistry (Aquariums): Always monitor your water parameters (pH, GH, KH) before and after dosing the aquarium to avoid sudden changes which can shock your aquatic life.