{"product_id":"life-rock-arch-12-4pk","title":"Life Rock Arch 12\" 4pk","description":"\u003cp\u003e\u003cstrong\u003eFour ready-made arches, and no cycling wait bolted onto the front of them.\u003c\/strong\u003e The CaribSea Life Rock Arch 4 pack contains four individually shaped arches of 12 inches (30 cm) each, in a box weighing around 20 lb (9 kg). Life Rock is a dry aquascaping rock built on an aragonitic base rock rather than cement, finished with engineered aragonite coatings that read as coralline algae, and infused with spored bacteria using CaribSea's AragAlive process. It needs no curing, carries no pests or algae, and goes into the tank the day it arrives.\u003c\/p\u003e\n\n\u003ch3\u003eKey features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFour 30 cm arches in one box\u003c\/strong\u003e - enough separate pieces to build a run of tunnels, or to stack into one taller structure with swim-throughs at two levels.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAragonitic base rock, not cement\u003c\/strong\u003e - CaribSea builds these on real aragonite rock, so the pH-neutral-to-alkaline behaviour and the surface texture match natural reef rock rather than moulded concrete.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAround 50% void space\u003c\/strong\u003e - a network of micro and macro pores running through each piece, which is where the bacteria that process ammonia and nitrite actually live.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpored bacteria infused\u003c\/strong\u003e - CaribSea's AragAlive treatment seeds the rock, which shortens the cycle rather than removing it.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNo curing, no die-off\u003c\/strong\u003e - this is dry rock. There is no ocean-collected life on it to rot, so there is no ammonia spike from the rock itself and no weeks of curing in a bin.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoralline-look coating\u003c\/strong\u003e - engineered aragonite coatings in muted reef colours, which CaribSea states are safe if grazed by tangs, urchins or snails.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e97% calcium carbonate\u003c\/strong\u003e - with minor and trace strontium, magnesium and barium, so it dissolves benignly rather than leaching anything unexpected.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat's in the box\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eFour Life Rock arches, 12 inches (30 cm) long each\u003c\/li\u003e\n\u003cli\u003eApproximately 9 kg of rock in total\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eNot included:\u003c\/strong\u003e base rock to sit the arches on, aquarium sand, reef putty or cement to bond the structure, and any bacterial starter you may want to add alongside. Each arch is individually shaped, so the arches you receive will not be identical to the photograph or to each other.\u003c\/p\u003e\n\n\u003ch3\u003eWill it fit my tank?\u003c\/h3\u003e\n\u003cp\u003eA 30 cm arch is the smallest of the three Life Rock arch sizes and the only one sold in multiples. That makes it the flexible option: you can run all four across a long tank, or use two and keep the others for a later rescape.\u003c\/p\u003e\n\u003cp\u003eOur rule of thumb for a feature rock is that it should span no more than about half the tank's length, so water can still move around and behind it. On that basis a single 30 cm arch sits comfortably in a tank from about 60 cm, and a row of two or three suits a 120 cm tank.\u003c\/p\u003e\n\u003cp\u003eAlso check height. An arch needs clearance above it for light and below it for fish, so a 30 cm arch wants roughly 40 cm of water depth to look like a swim-through rather than a shelf.\u003c\/p\u003e\n\n\u003ch3\u003eHow much rock do I need?\u003c\/h3\u003e\n\u003cp\u003eArches are structure, not the whole aquascape. Most reef tanks pair shaped pieces like these with plain base rock. The widely used guideline, and the one CaribSea's own Life Rock listings quote, is 1 lb of rock per US gallon of display volume - about 0.12 kg per litre. For a fuller scape with more caves and overhangs, 1.5 to 2 lb per gallon is the usual step up.\u003c\/p\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eDisplay volume\u003c\/th\u003e\n\u003cth\u003eMinimum rock (0.12 kg\/L)\u003c\/th\u003e\n\u003cth\u003eFuller scape (0.18 to 0.24 kg\/L)\u003c\/th\u003e\n\u003cth\u003eThis box covers\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e100 L\u003c\/td\u003e\n\u003ctd\u003e12 kg\u003c\/td\u003e\n\u003ctd\u003e18 to 24 kg\u003c\/td\u003e\n\u003ctd\u003eAbout three quarters of the minimum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e150 L\u003c\/td\u003e\n\u003ctd\u003e18 kg\u003c\/td\u003e\n\u003ctd\u003e27 to 36 kg\u003c\/td\u003e\n\u003ctd\u003eHalf of the minimum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e200 L\u003c\/td\u003e\n\u003ctd\u003e24 kg\u003c\/td\u003e\n\u003ctd\u003e36 to 48 kg\u003c\/td\u003e\n\u003ctd\u003eAbout a third of the minimum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e300 L\u003c\/td\u003e\n\u003ctd\u003e36 kg\u003c\/td\u003e\n\u003ctd\u003e54 to 72 kg\u003c\/td\u003e\n\u003ctd\u003eA quarter of the minimum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e450 L\u003c\/td\u003e\n\u003ctd\u003e54 kg\u003c\/td\u003e\n\u003ctd\u003e81 to 108 kg\u003c\/td\u003e\n\u003ctd\u003eA sixth of the minimum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e600 L\u003c\/td\u003e\n\u003ctd\u003e72 kg\u003c\/td\u003e\n\u003ctd\u003e108 to 144 kg\u003c\/td\u003e\n\u003ctd\u003eAn eighth of the minimum\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\u003cp\u003eModern reef aquascaping often runs deliberately below these figures to keep open sand and better flow. Treat the table as the upper bound of what a traditional scape uses, not a target.\u003c\/p\u003e\n\n\u003ch3\u003eWhich Life Rock arch do I need?\u003c\/h3\u003e\n\u003ctable\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003ePiece\u003c\/th\u003e\n\u003cth\u003eLength\u003c\/th\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003cth\u003ePieces per box\u003c\/th\u003e\n\u003cth\u003eSmallest tank we would use it in\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"\/products\/life-rock-arch-12-4pk\"\u003eLife Rock Arch 12\" 4pk\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003e30 cm each\u003c\/td\u003e\n\u003ctd\u003eAbout 9 kg per box\u003c\/td\u003e\n\u003ctd\u003e4\u003c\/td\u003e\n\u003ctd\u003e60 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"\/products\/life-rock-arch-xl-24\"\u003eLife Rock Arch XL 24\"\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003e61 cm\u003c\/td\u003e\n\u003ctd\u003eAbout 11 kg\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003ctd\u003e120 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003ca href=\"\/products\/life-rock-arch-mega-36\"\u003eLife Rock Arch Mega 36\"\u003c\/a\u003e\u003c\/td\u003e\n\u003ctd\u003e91 cm\u003c\/td\u003e\n\u003ctd\u003eNot published by CaribSea\u003c\/td\u003e\n\u003ctd\u003e1\u003c\/td\u003e\n\u003ctd\u003e180 cm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\u003c\/table\u003e\n\n\u003ch3\u003eDry rock is not live rock - what that means for your cycle\u003c\/h3\u003e\n\u003cp\u003eLife Rock is dry rock with bacteria added, not ocean-collected live rock. The practical difference cuts both ways and it is worth being clear about.\u003c\/p\u003e\n\u003cp\u003eWhat you avoid: die-off. Collected live rock arrives carrying sponges, worms and algae, much of which dies in transit and releases ammonia, which is why it has to be cured for weeks before it goes into a display. None of that applies here.\u003c\/p\u003e\n\u003cp\u003eWhat you still need to do: cycle the tank. The spored bacteria give the biological filter a head start, but a new system still has to build a population large enough for its stocking level. Add ammonia or a first fish slowly, and test until ammonia and nitrite both read zero before stocking properly.\u003c\/p\u003e\n\n\u003ch3\u003eSetting it up\u003c\/h3\u003e\n\u003col\u003e\n\u003cli\u003eUnpack over a towel. The arches are fragile in transit and the coating chips if a piece is dropped on a hard surface.\u003c\/li\u003e\n\u003cli\u003eDry-fit the structure outside the tank first. Arches are far easier to balance on a bench than under water.\u003c\/li\u003e\n\u003cli\u003eSeat the arches on the base of the tank or on base rock, not on the sand bed. Sand shifts and burrowing fish undermine anything resting on it.\u003c\/li\u003e\n\u003cli\u003eBond joins with reef-safe cyanoacrylate gel and putty if you are stacking. A 9 kg structure that topples onto a glass base is an expensive lesson.\u003c\/li\u003e\n\u003cli\u003eAdd sand around the base afterwards, so the rock is sitting on glass and the sand is dressed around it.\u003c\/li\u003e\n\u003c\/ol\u003e\n\n\u003ch3\u003eSuitable for, and not suitable for\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eSuitable for:\u003c\/strong\u003e marine fish-only and reef aquariums; new tanks being scaped from scratch; rescapes where you want more caves without buying more base rock; and African Rift Lake freshwater tanks, where the aragonite content works in your favour by holding pH and carbonate hardness up.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNot suitable for:\u003c\/strong\u003e planted aquariums, soft-water community tanks, blackwater and Amazonian biotopes, shrimp tanks and discus systems. This is calcium carbonate rock and it will raise pH and hardness. It is also not a substitute for cycling a new tank, and it is not the right choice if you specifically want the biodiversity that comes with collected live rock.\u003c\/p\u003e\n\n\u003ch3\u003eCare and maintenance\u003c\/h3\u003e\n\u003cp\u003eNo maintenance schedule applies to the rock itself. Over the first year the engineered coating is gradually overgrown by real coralline algae in a marine tank, at which point the pieces stop looking manufactured.\u003c\/p\u003e\n\u003cp\u003eBlow detritus out of the arch mouths with a turkey baster or powerhead at water changes. Enclosed shapes trap waste more than open rock does, and a tunnel full of detritus feeds nuisance algae.\u003c\/p\u003e\n\u003cp\u003eIf the coating chips during handling, the exposed aragonite underneath colours in on its own once coralline takes hold. It is cosmetic, not structural.\u003c\/p\u003e\n\n\u003ch3\u003eGoes well with\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/south-seas-base-rock-40lb-18kg\"\u003eCaribSea South Seas Base Rock 18kg\u003c\/a\u003e - the plain rock that makes up the bulk of a scape, so the arches stay the feature rather than the filler.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/arag-alive-fiji-pink\"\u003eCaribSea Arag-Alive Fiji Pink\u003c\/a\u003e - live aragonite sand to dress the base of the structure, from the same bacterial process.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/caribsea-purple-up\"\u003eCaribSea Purple-Up\u003c\/a\u003e - calcium and strontium supplement aimed at encouraging coralline algae to grow over the coating.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"\/products\/life-rock-arch-xl-24\"\u003eLife Rock Arch XL 24\"\u003c\/a\u003e - the single large arch, if you want one dominant span rather than four smaller ones.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWarranty and delivery\u003c\/h3\u003e\n\u003cp\u003eCaribSea does not publish a warranty term for Life Rock. Your rights under the Australian Consumer Law apply regardless and are not limited by anything the manufacturer does or does not offer.\u003c\/p\u003e\n\u003cp\u003eThe Australian distributor notes that because of the fragile nature of this rock, pieces can break in transit. Arches are the most breakage-prone shape in the Life Rock range, since the span is the weak point. A broken arch is still perfectly good rock and often makes two useful overhangs, but if you need the arch intact, unpack and check the box on arrival.\u003c\/p\u003e\n\n\u003ch3\u003eCommon questions\u003c\/h3\u003e\n\u003ch4\u003eDoes CaribSea Life Rock need to be cured before use?\u003c\/h4\u003e\n\u003cp\u003eNo. CaribSea states no curing is required. It is dry rock with no collected marine life on it, so there is nothing to die off and no ammonia released by the rock. You still need to cycle the aquarium itself before stocking.\u003c\/p\u003e\n\u003ch4\u003eHow many arches come in the box?\u003c\/h4\u003e\n\u003cp\u003eFour, each about 12 inches (30 cm) long, in a box weighing around 20 lb (9 kg). Every arch is individually shaped, so the four you receive will differ from each other and from the product photograph.\u003c\/p\u003e\n\u003ch4\u003eIs the purple coating safe if my fish pick at it?\u003c\/h4\u003e\n\u003cp\u003eCaribSea states the coating is safe if consumed by aquarium animals. Tangs, urchins and snails routinely graze it, and over time real coralline algae grows across it in a marine tank.\u003c\/p\u003e\n\u003ch4\u003eCan I use Life Rock arches in a freshwater tank?\u003c\/h4\u003e\n\u003cp\u003eYes, in hard alkaline freshwater. The rock is 97% calcium carbonate, so it raises pH and carbonate hardness - useful in an African Rift Lake tank, wrong in a planted, blackwater or shrimp setup.\u003c\/p\u003e\n\u003ch4\u003eDo I still need base rock as well?\u003c\/h4\u003e\n\u003cp\u003eIn most tanks, yes. At around 9 kg the box supplies a fraction of the rock a traditional scape uses, and arches are shaped as features rather than as bulk. Pair them with plain base rock and let the arches carry the structure.\u003c\/p\u003e\n\u003ch4\u003eWill the arches hold coral frags?\u003c\/h4\u003e\n\u003cp\u003eYes. The porous aragonite surface takes reef-safe cyanoacrylate well, and the underside of an arch is a good spot for low-light species that would burn on an exposed high rock.\u003c\/p\u003e\n","brand":"CaribSea","offers":[{"title":"Default Title","offer_id":55293347332387,"sku":"CS0389","price":368.95,"currency_code":"AUD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0972\/7236\/5347\/files\/life-rock-arch-12-4pk-10281463906595-1-dq.webp?v=1790372841","url":"https:\/\/nicksaquariumoceanariumterrarium.com.au\/products\/life-rock-arch-12-4pk","provider":"Nicks AOT","version":"1.0","type":"link"}