Review: Caribsea Life Rock ‘Shapes’

The days of having to choose between either unrealistic bone white dry rock, dirty dead reef rock or potentially pest-laden oceanic live rock are well and truly over with a number of manufacturers now offering realistic artificial reef rock. In this review, we take a look at the latest product in Caribsea’s already tried and tested life rock range… life rock ‘shapes’.

First of all, in terms of appearance, out of the current crop of rock options, we really think that Caribsea come closest to nailing the realism with this product. Life rock isn’t overly gaudy and looks just as good wet as it does dry. What makes their ‘shapes’ product even more attractive though is the variety of interesting forms that are available, with arching pieces, plate-like pieces and convoluted boulders all of which offer advanced aquascaping possibilites and provide a range of microhabitats for your fishes and invertebrates. We can’t see paint flaking being a problem with this range either, something which has been reported with other brands.

Aquascaping really is exceptionally easy with this rock even though it is perhaps slightly more dense than the highest quality oceanic rock. Pieces lock together readily to form a stable platform and the rock is durable in this process with even the inevitable tumbles and scrapes resulting in minimal chipping or loss of finish. Of course with rock of this kind this aquascaping can also be done dry and (having had several reef aquaria over the years) we find this hugely preferable to struggling with rock once it is in the aquarium… a process which inevitably leads to significant amounts of detritus, potential scratches to the tank walls and more often than not, a structure that is forever prone to instability. Aquascaping dry not only allows you to really take your time to perfect the structure but also then allows you to adhere the structure to provide long term stability and continuity for your reef. In short, you won’t have to worry about the whole thing collapsing and stressing (or directly damaging) your livestock every time you accidentally knock something with an algae magnet or tongs. On this subject, we used ITC Reefix for this process and it worked really well with our life rock (review coming soon!).

OK, so once this rock is in the tank and exposed to saltwater, a special coating of dormant bacteria becomes active and contributes to the establishment of effective nutrient cycling in the system. Frankly we aren’t really too concerned about this although it is ‘nice to have’. We think most people will already be planning to use a separate solution to cycle their aquarium anyway. What we would say is that it is certainly worth considering the inclusion of some supplementary media to provide additional matrix for denitrifying bacteria with this kind of product. We’d recommend the inclusion of such media with any of the artificial products currently on offer actually as although they are porous, they can’t match oceanic rock in this area just yet as far as we are aware.

That leads us onto the composition of this product and take note that this is billed as a ‘mined aragonite’ product. In short, it isn’t taken from the ocean so, on the face of it, there is less impact to the particular environment that we seek to replicate than with use of ocean rock. Of course this material used is also conducive to the chemical stability of the water in our reef tanks and with no organic material potentially hidden within the matrix (a problem with dry rock like ‘pukani’ which requires lengthy preparation, often involving powerful chemicals) the presence of Phosphates is also minimised.


Launched earlier in 2017, life rock shapes is already in high demand and retails for around £85 for a 9kg (20lb) box. This works out to be just under £10 per kilo, so it is cheaper than some of its competitors. Some of the other Carbisea life rock range (Belize Branch, Shelving etc) is slightly cheaper than this per kilo and given this we’d say it represents good value. We’ve included a shot of our 5x2x2 test system for reference below and take note that this included 2 boxes of ‘shapes’ and 2 boxes of ‘Belize Branch’. All-in-all we are mightily impressed with Caribsea and they also remain our first choice for substrates which we will be adding once the tank has been running for a few weeks.



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