Pack size
40 lb (18 kg) box
Water type
Marine
Part no.
CS0377
Life Rock Shelf Rock 40lb (18kg)
Instant reef structure that skips the months-long cure. CaribSea Life Rock Shelf Rock is an 18 kg (40 lb) box of aragonite base rock, cast with the same micro and macro pore network as natural reef rock and infused with dormant nitrifying bacteria that reactivate the moment the rock goes into water. The surface carries a manufactured texture and colouring designed to read as coralline growth from day one - it is not living coralline algae, and no living organisms ship with the box. What you are buying is a head start on the look and the biology, not livestock.
Key features
- Aragonite base, not cement - the same calcium carbonate structure as reef rock, so it buffers pH and carbonate hardness the way real reef rock does, rather than sitting inert like a resin imitation.
- Spored bacteria built in - dormant nitrifying bacteria are infused through the rock and reanimate once wet and fed an ammonia source, which is why this rock cycles faster than bare dry rock.
- Flat shelf face - each piece has a distinct flat side for stacking ledges, ledged caves and open coral-mounting surfaces, rather than the random lumps of a mixed box.
- No hitchhikers, no pest algae - because nothing living ships in the box, you are not gambling on aiptasia, bristleworm blooms or mantis shrimp the way you can with wild live rock.
- No reef harvested - it is manufactured, not quarried from a wild reef, so building a big aquascape does not cost a reef somewhere else its rock.
Specifications
| Pack size | 40 lb (18 kg) box |
|---|---|
| Pieces per box | Typically 5 to 6 pieces |
| Piece length | Approximately 20 to 36 cm (8 to 14 in) per piece |
| Shape | Shelf - one flat face per piece, for stacking and coral mounting |
| Material | Aragonite base rock with a manufactured coralline-mimicking surface texture |
| Biology at purchase | Dormant nitrifying bacteria infused through the rock; no living coralline, no hitchhikers |
| Effect on water | Buffers pH and carbonate hardness upward, as aragonite does |
| Water type | Marine only |
| Supplier code | CS0377 |
Which South Seas or Life Rock piece do I need?
| Product | Shape | Best for |
|---|---|---|
| Life Rock Shelf Rock | Flat shelf face | Coral mounting ledges, overhangs and the visible upper structure of the scape |
| South Seas Base Rock | Weathered, porous chunks | The bulk foundation underneath the display rock, where looks matter less than cost |
| South Seas Flatz | Sliced flat panels | Frag plugs, thin ledges and low-profile backgrounds |
Life Rock is the only one of the three that ships pre-seeded with bacteria and a coralline-look finish - the other two are unfinished dry rock, priced and used accordingly.
Setting it up
- Rinse each piece under fresh water to knock off loose dust before it goes in the tank.
- Build the aquascape dry first, on the tank floor or a dry-fit board, so the structure is stable before it is wet and heavy.
- Once placed, fill the tank and dose an ammonia source rather than food or a cleanup crew, so the bacteria have something to process without adding bioload too early.
- Test ammonia and nitrite through the cycle. Reef keepers commonly report Life Rock finishing a full ammonia cycle within one to two weeks, well inside the four to six weeks bare dry rock usually takes, though tank size, temperature and stocking plans all shift that timeline.
Suitable for, and not suitable for
Suitable for: reef tanks, FOWLR builds and any marine aquascape where you want mature-looking structure without a year of coralline growth. Safe to mount encrusting and branching corals directly onto the flat faces.
Not suitable for: freshwater aquariums of any kind - the aragonite base will push pH and hardness up, which is exactly wrong for a community or planted freshwater tank. If you want dramatic freshwater rock, see CaribSea's Mountain Stone instead.
Goes well with
- CaribSea South Seas Base Rock - a cheaper porous foundation to bulk out the base of the scape under the Life Rock shelves.
- CaribSea Seaflor Special Grade Reef Sand - an aragonite sand bed that buffers the same way this rock does, for a matched water chemistry.
Warranty and delivery
CaribSea does not publish a warranty term for its rock. Your rights under the Australian Consumer Law apply regardless. The box weighs 18 kg, so factor that into freight if you are ordering more than one.
Common questions
Is Life Rock actually alive when it arrives?
No. It ships dry with dormant bacteria infused through the rock and a manufactured surface designed to look like coralline algae. Nothing living travels in the box - the bacteria reactivate once the rock is wet and fed, and real coralline growth develops over time in your tank, the same as it would on any rock.
Do I still need to cycle my tank with this rock?
Yes, but it is faster. The dormant bacteria give the nitrogen cycle a head start compared with bare dry rock, but you still need to run ammonia through the system and test before adding livestock.
Can I mix Life Rock with regular dry rock?
Yes. Many reef keepers use Life Rock for the visible structure and cheaper dry rock such as South Seas Base Rock underneath, where it will not be seen.
Will it raise my pH too high?
It buffers pH and KH upward the way any aragonite-based rock does, which is what a reef tank wants. It is not suitable for freshwater for the same reason.