• Sliced on two sides - flat faces sit flat and stack square, so ledges and platforms hold their position instead of rocking on a curved contact point.
• Pieces from about 5 cm to 25 cm - the small slices cap, level and shim; the large ones carry the weight underneath.
• No curing - this is dry rock infused with living spored bacteria, so there is no die-off, no ammonia spike from the rock itself and no weeks in a curing bin.
• Coralline-toned coating - the purple colouring is on the rock from new, rather than a bare white scape you wait a year to colour up.
• Real aragonitic base rock, not cement - nothing to leach out and no cement cure to manage before livestock goes in.
• Flat tops take frags directly - CaribSea positions Flatz for fragging corals of all sizes, so plugs glue straight to the shelf without a separate frag rack.
• Tiles across the tank bottom - CaribSea specifically suggests Flatz for rock footers and sandless substrate beds, tiled in across the base.
• Hand crafted and unique - each piece is individually made, so shapes and the exact mix in a box vary. Product photos are representative.

This is the question a rock page has to answer, and the honest version has two parts.

For total rock in the tank, CaribSea's own published guidance is one 40 lb (18.14 kg) Dreamscapes Assortment Box for every 40 to 60 US gallons. Converted to litres and worked back, that is roughly 0.08 to 0.12 kg of rock per litre of display volume.

The part most rock pages leave out

Those figures are for the whole aquascape. Flatz is a shaping rock rather than a bulk base rock, and most scapes use one box of Flatz alongside a larger quantity of chunkier rock rather than building the entire structure from slices.

A practical split for a 200 L reef is one box of Flatz for the shelves, caves and frag platforms, with the bulk of the structure made up from LifeRock Original or LifeRock Shapes.

The low end of the range suits open, minimalist scapes with plenty of swimming room. The high end suits dense, cave-heavy rockwork. Modern reefkeeping has moved towards the lower end, because flow and light both reach further through an open structure.

The LifeRock range is sorted by shape rather than by quality, and most scapes mix two or three of them. This is what each one is for.

If you would rather not select shapes yourself, the LifeRock Dreamscapes Aquascaping Kit supplies a matched assortment sized to the tank.

1. Rinse lightly in clean fresh or saltwater. This is only to wash off loose dust and fines, not to clean or cure the rock.
2. Dry-fit the scape outside the tank first. Flat faces let you test a stack on the bench and rebuild it the same way in the tank.
3. Build from the bottom up, seating the largest slices directly on the bare glass wherever you can, so nothing is resting on sand that a fish can later excavate.
4. Check every shelf holds under a firm push before you add water. A ledge that moves under your hand will move under a tang.
5. Add water gently onto a plate or bag rather than straight onto the sand bed.

Aquascaping mortar or reef-safe cyanoacrylate gel is not supplied with the box. Flatz is designed to stack without it, but for tall or cantilevered shelves in a high-flow tank it is worth bonding the joints.

Suitable for: marine and reef aquariums of any size; frag tanks and frag shelves; sumps and refugia, where broken slices add biological surface area; African cichlid aquariums, which want the same hard, alkaline water this rock produces.

Not suitable for: planted freshwater aquariums, soft-water community tanks, blackwater and Amazonian setups, shrimp tanks and discus systems. CaribSea is explicit that LifeRock raises pH and alkalinity and should only be used in marine, reef or African cichlid tanks - that buffering is not something you can switch off. For a freshwater hardscape, use Dragon Stone Freshwater Rock instead.

The rock itself needs no replacement schedule. Aragonite dissolves extremely slowly, so a scape built today is still a scape in ten years.

What does need attention is detritus. Flat shelves collect settled waste on their top surfaces, which is the trade-off for the surface area they give you. A turkey baster or powerhead blast across the shelves at each water change moves it into the water column where the filter can catch it.

The factory coating is cosmetic and mimics mature coralline algae. Real coralline will colonise the rock over time in a tank with stable alkaline chemistry and adequate calcium and magnesium.

• CaribSea LifeRock Original 40lb - the bulk base rock most scapes need underneath the shelving.
• CaribSea Arag-Alive Live Reef Sand - an aragonite sand bed that matches the rock chemistry rather than working against it.
• CaribSea Purple-Up - calcium and trace supplement aimed at accelerating real coralline growth over the factory colouring.
• CaribSea LifeRock Shrooms - ready-made pinnacles for height, where stacking slices would be unstable.

CaribSea does not publish a warranty term for its aquascaping rock. Your rights under the Australian Consumer Law apply regardless and are not limited by anything the manufacturer does or does not offer.

Rock is fragile in transit and slices are more fragile than chunks. Some chipping in a box of hand-made rock is normal, and broken pieces are still usable - a clean break can be rejoined with reef-safe gel or simply built into the scape. Each box is 9.07 kg, so check the freight total before ordering several.

Does CaribSea LifeRock Flatz need curing before it goes in the tank?

No. CaribSea states that LifeRock does not need curing, and suggests only rinsing lightly with clean fresh or saltwater to remove any loose particles before placing it in the aquarium. It is dry rock, so there is no die-off to rot out and no ammonia produced by the rock itself.

Is this live rock?

No. LifeRock Flatz is dry aquascaping rock that has been infused with living spored bacteria, which activate once the rock is in saltwater. It seeds a cycle rather than replacing one, and it carries none of the sponges, worms and hitchhikers - wanted or unwanted - that come with collected live rock.

Can I use LifeRock Flatz in a freshwater tank?

Only in an African cichlid tank. CaribSea states that LifeRock raises pH and alkalinity and should only be used in marine, reef or African Cichlid aquariums. It is the wrong rock for a planted tank, a soft-water community tank or a shrimp tank.

How many pieces are in a 20 lb box?

CaribSea does not publish a piece count for Flatz. Because every piece is hand made and the size range runs from about 5 cm to 25 cm, the count varies from box to box - a box weighted towards large slices contains fewer of them.

Will the purple colour fade?

The colouring is a coating applied by CaribSea to mimic mature coralline algae, not live coralline, so it does not grow or spread on its own. Over months in a stable reef tank, real coralline algae typically colonises the rock and takes over the appearance.

Do I need glue or aquascaping cement?

Not for a conventional stacked scape - the two sliced faces are what make Flatz stable without adhesive. Bonding is worth it for tall pinnacles, cantilevered shelves and any structure in strong flow, and it is not supplied in the box.