The use of lava rock in a saltwater aquarium can bring many benefits to the aquarist and this article covers some of them. In nature, corals are selectively seeded onto specific hard substrates by various means.
Some creatures bear eggs that eventually grow into coral polyps while others secrete a mucous thread onto rocks from which the polyps eventually develop. However, in the aquarium, these processes cannot take place and corals must be attached to something to stay alive and continue growing.
Throughout the year’s many different substrates have been used with varying results. The main thing is that they should be able to support life and not cause any problems in the aquarium such as releasing substances that may be harmful to other inhabitants.
Some substrates that have been used in the past include shells, sand, and gravel. These can be prepared in a variety of ways including sterilizing them with boiling water or using pulverizers to remove even the tiniest pieces from them. It is also possible to buy these products already sterilized.
Another material that has been used is crushed coral. This may be bought already prepared for aquarium use or it can be obtained from places where shells are broken down to extract the mother of pearl. This product must be thoroughly rinsed before use because dirt and other residues may remain after processing.
After this, the material should be completely dry before being placed in the aquarium because any excess moisture can be harmful. The addition of crushed coral to an aquarium is usually done on a small scale but some aquariologists use large pieces or even live rock which may contain quite a few corals on it.
The use of this type of substrate does not always guarantee success with corals and some types should be avoided altogether. Some of these include limestone and dolomite which should never be used because they contain calcium carbonate which is harmful to invertebrates.
Oyster shells, marble, and pumice are also not advisable as they can alter the pH value of the water as well as contain other undesirable substances such as iron oxide in the case of pumice. Shale and slate are also not recommended because they may affect the pH value through their high silica content.
The next thing to look at is whether the material in question can be used successfully in a marine aquarium or an aquarium that contains both saltwater fish and invertebrates. Invertebrates are extremely sensitive to the water flowing over their bodies. They can even be killed by a sudden change in temperature, which is why it should only be used for tanks intended for them.
The next benefit of using lava rock is that there are several variations on the market and these come in different shapes and sizes depending on what they were formed from. These are usually different colors but the main thing is that they should be quite dark because this is more attractive to invertebrates.
The next thing about lava rock is that it emits calcium which helps with the proper development of corals. It also contains substances that will bring out natural colors in invertebrates and stimulate their growth as well as aid reproduction.
However, it is important not to overdo the use of lava rock because if the level of calcium and other substances in the tank increases too much there can be problems. The water will become quite an alkali and this type of environment is harmful to invertebrates. This can be avoided by using a special material that removes excess calcium from the water.
For larger aquariums, it is possible to have a central area that is filled with lava rock and this can be surrounded by other areas on which coral is grown. In addition, some aquarists add a percentage of crushed coral to their marine aquariums to provide additional nutrients for growing corals while at the same time maintaining the pH levels at their normal level.
Other materials can also be added to aquariums to provide a more natural habitat for invertebrates. These include clay which helps with the development of live rock as well as protecting from burrowing organisms such as worms and mollusks.
It is also possible to buy small shells that will help develop reefs and these can come from areas where they are harvested such as the Gulf of Thailand.
Some aquarists will also add pumice to their aquariums to provide a more solid base for growing corals and this is particularly useful when there is a lot of movement in the water because it provides a much firmer foundation.