The first thing that comes into mind when establishing a reef aquarium tank is the aquascaping concept with the addition of live rock. In the past, all these were actually harvested from the ocean and because of controversies surrounding conservatory efforts and sustainability concerns, live rocks were artificially cultured in large marine aquatic farms and then offered for sale in local pet shops. Establishing healthy population of these living rocks not only offer aesthetic value and enhance appearance of the overall fish tank but it also plays a pivotal role that act as a natural filtration system to clean the water.
There are different types of live rocks depending on the location on where it was obtained and each has its own individual properties in terms of physical and chemical attributes. Some of it has to potential to change the aquarium water chemistry by slowly biodegrading in the water and then releasing active chemical compounds. These types are those generally considered unsuitable for use in the reef hobby. A good example would be volcanic and lava rocks which will leach excessive nutrient into the water and disrupt the natural balance of enclosed marine tank ecosystem. Thus, those which are overall inert under extreme condition and chemically stable in the long run are selected and these usually command higher selling price due to ever-increasing demands in the market. Let’s look at some of the options available for those reef tank fanatics.

This one is considered one of the favorites among the circle of die-hard hobbyist due to its light weight feature and its fascinating shapes. Some consider it unique and able to fit into any aquascaping plan. One word of caution though because rocks originated from this locality made available in pet shops are usually not properly cured while most of the aquatic life associated with the original rock has already died off.
Fiji Rock
Most of these special rocks that are sold in fish stores come with attached biodiversity of natural inhabitants still surviving on its surface and its porous structure and one of the great features on why it was selected is because of the colorful glowing appearance especially the purple color type. Overall, it has great coralline growth and the shape is rounder. Price wise, it is cheaper and more affordable to general aquarist. Look for medium-sized Fiji rocks to complement the larger types and some people actually stack them together to create a small pile in the middle of the tank.
Tonga Branch
Easily identified due to its branch-like structure but these days due to licensing restrictions in the country coupled with high demand, supply is very scarce and nowadays not many shops offer it for sale. It is considered a valuable piece of show rocks.
Vanuatu Rock
These are usually available in large slab form and thus used as a bottom base for aquascaping combined with the other types of rocks of different shapes. It can be quite expensive due to its quality and location from where it was taken from as it has to travel from Australia over to Europe and America. Somehow there are always limited stocks available and some so-called Vanuatu live rocks are actually those bought in from Indonesian islands and also across the Philippines reefs sanctuary.
Aquacultured Rock
Using these artificial rocks is considered environmental friendly approach as it does not involve destruction of natural ecosystem that comes from the process of collecting and harvesting from reefs. Specialized farm owners involved in the business will usually dump normal ground rocks or some cement blocks into the water and wait for the natural process to occur with growth of microorganisms and living creature to establish population on its surfaces. Some different approaches involve artificial aquaculture practice taking place in large aquarium tanks instead. Depending on the types of man-made building materials used for the construction, some are quite fragile.
Use of live rocks has its fair share of disadvantages basically on the introduction of unwanted pest such as predatory mantis shrimp that can wreck havoc in your fish tank and other unwanted guest includes aiptasia, worms, crabs and sea spiders that are equally devastating to the reef tank. That is why hobbyist these days would rather purchase a whole complete set of reef ready aquarium so that they don't have to go through all the trouble of aquascaping and then selecting individual rocks, as all these have been professionally done by the experts.
Related reef aquarium subject: Choice of decor for your marine tank and adding reef compatible bass anthias. Guide on selecting the correct reef-safe wrasse