Oyster shell

Crushed Oyster Shell | Essential Bioactive Calcium Supplement

Maintain a thriving ecosystem with our Crushed Oyster Shell. This professional-grade substrate amendment is the secret to success for long-term bioactive enclosures — providing a slow-release source of calcium and essential minerals to keep your clean-up crew healthy, productive, and structurally sound. Sold in 25g bags.

Why It’s a Bioactive Essential

• Superior Moulting Support: Invertebrates like isopods, millipedes, and springtails need consistent calcium to successfully harden their new exoskeletons after a moult. Crushed shell provides a constant grazing source to prevent moulting failures.
• Natural pH Buffer: As organic waste and leaf litter break down, substrate can become acidic. These crushed shells act as a natural buffer, neutralising acids and keeping your soil chemistry balanced.
• Texture & Aeration: When mixed into the soil, the grit helps prevent substrate compaction, allowing better oxygen flow to terrarium plant roots and more room for micro-fauna to burrow.
• Breeding Boost: Many keepers find that isopod colonies — particularly Armadillidium species — see a significant boost in breeding rates when mineral grit is readily available.

Product Details

Usage Tip: For best results, mix 1–2 tablespoons per gallon of substrate during initial setup. For established enclosures, simply top-dress by sprinkling a light layer under your leaf litter or near your hydration station where isopods naturally congregate.

❓ Frequently Asked Questions

How much oyster shell should I add to my enclosure?
Mix 1–2 tablespoons per gallon of substrate during initial setup. For established enclosures, top-dress with a light layer under leaf litter or near the hydration station. You can also place a small pile directly on the substrate surface for isopods to graze on.

Will oyster shell raise the pH too much?
No — crushed oyster shell acts as a gentle buffer rather than a strong alkaliser. It neutralises excess acidity from organic breakdown without pushing pH to harmful levels. It is safe for all tropical and temperate isopod species.

Is it safe for all isopod species?
Yes — crushed oyster shell is safe for all isopod species including Armadillidium, Porcellio, Cubaris, and Trichorhina. It is particularly beneficial for Armadillidium species, which have a high calcium requirement.

Can I use it in a jumping spider enclosure?
Yes — a small amount mixed into the substrate of a bioactive jumping spider enclosure helps support any isopod or springtail clean-up crew and maintains healthy soil chemistry.

How often should I replenish it?
In an active colony, replenish every 4–8 weeks or when you notice the surface layer has been consumed. In less active setups, it may last several months before needing a top-up.