Pack size
40 lb (18 kg) box, approx. 10-14 loose pieces
Water type
Marine
Part no.
CS0376
Life Rock Original 40lb (18kg)
Dry, silicate-free base rock that starts cycling the moment it hits saltwater. CaribSea Life Rock Original is an aragonite base rock sold as a 40 lb (18 kg) box of loose, irregular pieces, built to be the main footprint of a reef aquascape. It is dry-shipped, so there is no die-off, no curing period and no smell to work through - the rock is pre-coated with an artificial texture that mimics natural coralline algae and infused with dormant bacteria that activate as soon as it goes into saltwater, kick-starting the nitrogen cycle rather than adding to it.
Key features
- Aragonite base, not cement - CaribSea builds Life Rock from an aragonitic base rather than the moulded cement used by some artificial rock, so it carries a genuine reef mineral profile through the tank's life.
- Micro and macro pore network - the porous structure gives nitrifying bacteria far more surface area to colonise than a solid rock of the same size would.
- Pre-coated to look established - the coralline-mimicking texture means the scape reads as "in" from day one, while real coralline algae fills in over the top as the tank matures.
- No curing required - nothing organic died to produce this rock, so there is no ammonia spike to wait out before you aquascape.
- Zero wild-collection risk - it is manufactured, not reef-harvested, so it does not arrive carrying aiptasia, bristleworms, mantis shrimp or other hitchhiker pests the way ocean live rock can.
- Every piece is unique - natural, irregular shapes and sizes. The product photo is representative of the range you will receive, not a guarantee of the exact pieces in your box.
How much do I need?
The industry rule of thumb for dry base rock is roughly 1 lb per US gallon of display volume as a starting point, which converts to about 0.12 kg per litre. That figure assumes a moderate, fairly solid-looking aquascape - build open, reef-style with large negative space for flow and coral placement and you will use noticeably less rock for the same visual impact.
| Tank volume | Rock at ~0.12 kg/L (moderate scape) | 18 kg boxes needed |
|---|---|---|
| 100 L | ~12 kg | 1 |
| 150 L | ~18 kg | 1 |
| 200 L | ~24 kg | 2 |
| 300 L | ~36 kg | 2 |
| 450 L | ~54 kg | 3 |
Buy a little short rather than a little over. It is far easier to add a second box than to store rock you did not end up needing.
Specifications
| Pack weight | 40 lb (18 kg) per box |
|---|---|
| Pieces per box | Typically around 10-14 loose, irregular pieces, ranging from fist to football sized |
| Material | Aragonite base rock with an artificial coralline-mimicking coating |
| Bacteria | Pre-infused, dormant until placed in saltwater |
| Curing required | No |
| Water type | Marine and reef aquariums |
| Effect on water | Aragonite base - raises and buffers pH and carbonate hardness, the same as CaribSea's other aragonite products |
| Supplier code | CS0376 |
Which Life Rock format do I need?
| Product | Format | Pack | Best for |
|---|---|---|---|
| Life Rock Original | Loose, assorted base pieces | 40 lb (18 kg) box | Building the main footprint of a reef aquascape from scratch |
| Life Rock Shapes | Loose arches, rings and tunnels | 20 lb (9 kg) box | Adding open swim-throughs to a scape you are building yourself |
| Life Rock Reef Tree Kit | Pre-shaped branching kit on a stabilising rod | 4 pieces | A ready-made vertical centrepiece, no loose-rock aquascaping needed |
| Life Rock Reef Tree Arches Kit | Pre-shaped kit built around open arches, on a rod | 4 pieces | The Reef Tree look, weighted toward tunnels and overhangs |
| Life Rock Reef Tree Extension Kit | Add-on pieces plus a short rod | 2 pieces | Adding height or width to a Reef Tree Kit or Arches Kit you already own |
Suitable for, and not suitable for
Suitable for: building the base layer or full structure of a new marine or reef aquascape; reef keepers who want an established coralline look immediately rather than waiting months for real algae to spread; anyone who wants to avoid the pest risk that comes with ocean-collected live rock.
Not suitable for: freshwater aquariums - this is formulated, coated and marketed as a marine reef product, not a freshwater hardscape stone. If you want dry rock for a freshwater or cichlid tank, CaribSea's Mountain Stone and Dragon Stone ranges are the freshwater-specific options.
What's in the box
One 18 kg box of loose Life Rock Original pieces. There is no stabilising rod, cement, mortar or tools included - this is freeform aquascaping rock, stacked and arranged by hand. If you want a pre-shaped, self-supporting structure instead, see the Reef Tree Kit range in the comparison table above.
Setting it up
- Rinse the pieces under tap water to clear shipping dust - this is a courtesy rinse, not a cure, and does not remove the bacterial coating.
- Dry-stack your aquascape outside the tank first. Life Rock is rigid enough to test different arrangements before anything touches water.
- Place the finished structure directly on the glass base, not on top of sand, so it cannot topple if a fish or a future sand-sifter digs underneath.
- Fill the tank and start the filter. The bacterial coating begins working immediately; there is no separate cycling step required beyond the normal check that ammonia and nitrite are reading zero before livestock goes in.
Goes well with
- CaribSea Life Rock Shapes - loose arches, rings and tunnels to break up a scape built mostly from Original base pieces.
- CaribSea Seaflor Special Grade Reef Sand - a sand bed in the same aragonite family, styled to sit under a Life Rock structure.
- Aquascaping mortar or rock-bonding putty (sold separately) - for permanently fixing a tall or top-heavy structure before livestock is stocked around it.
Warranty and delivery
CaribSea does not publish a warranty term on its rock products. Your rights under the Australian Consumer Law apply regardless, and are not limited by anything the manufacturer does or does not offer.
Each box weighs 18 kg. A larger tank built at 2-3 boxes adds up quickly on freight - check the total before ordering multiples.
Common questions
Do I need to cure CaribSea Life Rock before adding it to my tank?
No. Curing exists to let organic matter on wild live rock die off and be removed before it fouls the water. Life Rock is manufactured, not reef-harvested, so there is nothing to die off - a courtesy rinse to clear shipping dust is the only preparation it needs.
Will real coralline algae grow over the artificial coating?
Yes, over time, under reef lighting and with stable water parameters. The pre-applied coating gives the scape an established look immediately; genuine coralline growth fills in on top of it as the tank matures.
Can I use Life Rock Original in a freshwater tank?
No. It is formulated and coated for marine and reef use. For a freshwater aquascape, use a freshwater-specific CaribSea rock such as Mountain Stone or Dragon Stone.
Will it raise my pH?
Yes, gradually. Like CaribSea's other aragonite-based products, Life Rock buffers water toward higher pH and carbonate hardness, which suits standard reef parameters and is not something you can switch off.
Is every box the same mix of shapes?
No. Pieces are natural and irregular, so the exact shapes, sizes and piece count vary box to box within the stated weight. The product photo is representative of the range, not a guarantee of what you will receive.