CaribSea Geo-Marine Florida Crushed Coral is a natural aragonite-based substrate designed for marine, brackish, and hard-water freshwater aquariums. As the only crushed coral substrate containing natural aragonite, it provides up to 25 times the buffering capacity of ordinary crushed corals, dolomite, or oyster shells. This coarse, high-performance substrate eliminates chronic pH drops, maintains essential calcium and carbonate levels, and offers an massive surface area for beneficial nitrifying bacteria to thrive.
Key benefits
Superior pH Buffering: Slowly dissolves to naturally raise and stabilize pH and carbonate hardness (KH), preventing dangerous pH swings.
Massive Biological Surface Area: The porous structure supports large colonies of water-purifying bacteria, allowing you to increase your tank's bioload by up to 50%.
Releases Essential Minerals: Naturally delivers calcium, carbonate buffers, and critical trace elements like strontium (up to 10,000 ppm) directly to the water column.
Ideal for High-Flow Tanks: The coarse, heavy grain size stays in place and will not blow around or create bare spots under high-output wavemakers.
Never Needs Replacing: Unlike synthetic buffers that deplete quickly, this natural substrate provides long-lasting, gradual buffering that continues to feed your system's biological cycle.
Specifications
Net weight: 40 lb (approx. 18.1 kg)
Form: Coarse dry gravel / crushed coral
Grain Size: Mixed grade (approx. 2.0 mm to 5.5 mm)
Primary purpose: Substrate, pH/KH buffering, and biological filtration media
Water type: Saltwater, brackish, and hard freshwater (such as African Cichlid setups)
Suggested use
Rinsing: Rinse the substrate thoroughly in a bucket with clean water before placing it in the tank to remove fine dust and minimize initial cloudiness.
Placement: Gently spread a 1- to 2-inch layer along the bottom of the aquarium.
Alternative use: Place in a mesh media bag inside your canister filter, sump, or media reactor for controlled, adjustable pH buffering without changing your primary sand bed.
Suitability: Best suited for high-flow setups. Not recommended for sand-sifting or bottom-dwelling species that require very fine, soft sand.
Ingredients
100% natural marine aragonite, crushed coral. Free of ash, metals, pesticides, and silica.
Guaranteed analysis
Calcium Carbonate (CaCO3): Min 98%
Magnesium Carbonate (MgCO3): Min 1%
Strontium (Sr): Up to 10,000 ppm
Storage and safety
Store in a dry place.
Keep out of reach of children.
Warnings
For aquarium use only. Not for human consumption.
Will naturally raise pH and hardness. Do not use in aquariums requiring soft, acidic water (such as planted tanks, discus tanks, or soft-water community setups).
What’s included
1 x Bag of CaribSea Florida Crushed Coral (40 lb)
Why choose
CaribSea Florida Crushed Coral is the industry standard for stabilizing pH and bolstering biological filtration in marine and African cichlid aquariums. By using pure aragonite rather than standard terrestrial gravels, it prevents chronic acidity and supplies crucial trace minerals. This heavy-duty 40 lb bag provides plenty of coverage for medium-to-large setups, giving your hard-water species the stable, healthy environment they need to thrive.
CaribSea Geo-Marine Florida Crushed Coral is a natural aragonite-based substrate designed for marine, brackish, and hard-water freshwater aquariums. As the only crushed coral substrate containing natural aragonite, it provides up to 25 times the buffering capacity of ordinary crushed corals, dolomite, or oyster shells. This coarse, high-performance substrate eliminates chronic pH drops, maintains essential calcium and carbonate levels, and offers an massive surface area for beneficial nitrifying bacteria to thrive.
Key benefits
Superior pH Buffering: Slowly dissolves to naturally raise and stabilize pH and carbonate hardness (KH), preventing dangerous pH swings.
Massive Biological Surface Area: The porous structure supports large colonies of water-purifying bacteria, allowing you to increase your tank's bioload by up to 50%.
Releases Essential Minerals: Naturally delivers calcium, carbonate buffers, and critical trace elements like strontium (up to 10,000 ppm) directly to the water column.
Ideal for High-Flow Tanks: The coarse, heavy grain size stays in place and will not blow around or create bare spots under high-output wavemakers.
Never Needs Replacing: Unlike synthetic buffers that deplete quickly, this natural substrate provides long-lasting, gradual buffering that continues to feed your system's biological cycle.
Specifications
Net weight: 40 lb (approx. 18.1 kg)
Form: Coarse dry gravel / crushed coral
Grain Size: Mixed grade (approx. 2.0 mm to 5.5 mm)
Primary purpose: Substrate, pH/KH buffering, and biological filtration media
Water type: Saltwater, brackish, and hard freshwater (such as African Cichlid setups)
Suggested use
Rinsing: Rinse the substrate thoroughly in a bucket with clean water before placing it in the tank to remove fine dust and minimize initial cloudiness.
Placement: Gently spread a 1- to 2-inch layer along the bottom of the aquarium.
Alternative use: Place in a mesh media bag inside your canister filter, sump, or media reactor for controlled, adjustable pH buffering without changing your primary sand bed.
Suitability: Best suited for high-flow setups. Not recommended for sand-sifting or bottom-dwelling species that require very fine, soft sand.
Ingredients
100% natural marine aragonite, crushed coral. Free of ash, metals, pesticides, and silica.
Guaranteed analysis
Calcium Carbonate (CaCO3): Min 98%
Magnesium Carbonate (MgCO3): Min 1%
Strontium (Sr): Up to 10,000 ppm
Storage and safety
Store in a dry place.
Keep out of reach of children.
Warnings
For aquarium use only. Not for human consumption.
Will naturally raise pH and hardness. Do not use in aquariums requiring soft, acidic water (such as planted tanks, discus tanks, or soft-water community setups).
What’s included
1 x Bag of CaribSea Florida Crushed Coral (40 lb)
Why choose
CaribSea Florida Crushed Coral is the industry standard for stabilizing pH and bolstering biological filtration in marine and African cichlid aquariums. By using pure aragonite rather than standard terrestrial gravels, it prevents chronic acidity and supplies crucial trace minerals. This heavy-duty 40 lb bag provides plenty of coverage for medium-to-large setups, giving your hard-water species the stable, healthy environment they need to thrive.
