The current trend is to setup new saltwater aquariums using live rock. Another option that some people choose is to decorate with dead corals or man-made decorations giving the aquarium a sterile, artificial appearance. The natural look of live rock is the main reason people choose this method. While aesthetically a great shift, using live rock also has many health benefits for the fish.

One key to success with saltwater aquariums is to keep the inhabitants as relaxed as possible. Using dead corals and artificial décor to decorate the aquarium does make the fish comfortable. Initially the aquarium looks pristine and beautiful, but as algae grows on the decorations it gives the aquarium a dirty look. In order to keep the aquarium looking beautiful, the decorations are removed and cleaned. The fish and invertebrates are disturbed because they use the decorations to setup territories or for hiding places. When the decorations are put back in the aquarium the struggle for territories begins again.

Though algae grows on live rock [just like on the artificial decorations] it looks and is natural. Live rock does not need to be removed for cleaning. There are also fish and invertebrates that feed on algae, keeping it under control. Live rock is porous, with plenty of surface area. This allows beneficial bacteria to colonize and break down waste.

The benefits of using live rock far outweigh the negative but there is a down side. Sometimes a fish grows too large, becomes aggressive or maybe gets sick; and it becomes necessary to remove it from your aquarium. This sounds like a simple task, but sometimes fish are difficult to catch. Imagine an aquarium stacked with live rock with lots of caves, hiding places and crevices into which a net cannot reach. You may have to remove some or most of the live rock to catch a fish. This is really not a big deal but it does take some time and patience.

Okay, so live rock is the way to go but what is it? Live rock as its name suggests is rock with living organisms (animals, plants, algae, bacteria, etc.) attached to and growing on and in it. Live rock is collected from oceans in different parts of the world with collection sites in tropical areas such as Fiji, Marshall Islands, Tonga, Bali, Indo-Pacific, etc. Most live rock is named for the area in which it is collected.

Live Rock makes up the backbone of any Fish Only With Live Rock (FOWLR) or reef aquarium. It is available in two forms: cured and uncured rock. Depending on whether the aquarium is new or established determines whether you choose cured or uncured.

Uncured rock is rock removed from the ocean, wrapped in newspaper and shipped to your local pet and aquarium store. During shipping much of the animal and plant life on the rock are damaged. When this live rock is placed into an aquarium the damaged and dying organisms send the levels of waste very high. Uncured rock put directly into an existing aquarium causes ammonia levels to spike, creating distress and/or killing existing livestock in the aquarium. Therefore uncured rock is primarily used when setting up a new aquarium with no other inhabitants.

Many pet and aquarium stores will take uncured live rock through a process called curing. Once live rock has gone through this process it is considered cured live rock. Even though this rock is cured caution should be used when adding it to an existing aquarium with livestock. If you already have an aquarium stocked with fish, add live rock slowly over time. Adding a large amount of cured live rock at one time could make your ammonia level spike, which will stress your fish and invertebrates.

When setting up a new aquarium you can add as much live rock as you like because there are no other animals present. Generally you use about ¾ to a 1 ½ pounds of live rock per gallon of water. The weight of the live rock varies depending on how dense and porous it is. You can wait a week or two after adding uncured live rock before testing the levels of ammonia and nitrite. When these levels are at zero it is time to do a water change, ensure your pH is correct and then add fish and/or invertebrates.