Saltwater or marine aquarium is an aquarium that houses fish, corals, plants, and other species that live in ocean or marine water.

Building saltwater aquarium takes more efforts and costs than building freshwater aquarium; there are main factors that require attention and acts before having a perfect-beautifully looking aquarium. Those factors are:

• Water salinity

• Water lighting

• Water temperature

A bit explanations about those factors are as follow:

Salinity is dissolved salt concentration in aquarium water. The water salinity can increase or decrease depending on how much you add salt into the water. You can measure the water salinity by using aquarium hydrometer or refractometer. By using this tool, you will know how salty the water is and whether it meets the requirements needed by the saltwater fish you're going to put in the aquarium or not.

Controlling the water lighting system in saltwater aquarium is also very important, since saltwater or marine fish and other living creatures depend greatly on the sun lighting.

When deciding what kind of fish, coral, or any other living creatures you're about to house in the saltwater aquarium, you must also think of the condition of their own habitats in nature; whether they live in sun-lighted areas or deep areas under the sea. This is very important, because ignorance of this information will bring your fish or other living creatures in your saltwater aquarium get stress.

For example, you can not turn off completely the aquarium lighting system if you decide to house living corals inside the aquarium, otherwise they will die because they are not used to live in dark water. The same condition also happens to the saltwater fish. Eventhough the ocean is dark at night, there is at least lunar light that constantly shines. That is why you had better have a controllable lighting system which can manipulate the lighting condition in the ocean at any time.

Another important factor you should keep in mind is to control the temperature of the saltwater aquarium. This is because ocean fish do not inhabit the same temperature areas in the ocean, in fact they live in different temperature areas of water.

There are fish that can live in dark and shady ocean's depth, where the temperature is temperate or cold. However, tropical fish and corals live in warm, shallow ocean water. If you have tropical fish in your saltwater aquarium, you may not let the water go too cold, so must use water heater to warm it again.

You have to carefully measure and maintain the aquarium temperature in order to avoid stress happening to the fish and other living creatures there. Furthermore, failure to maintain the temperature will also cause algae break which will threaten the fish' lives.

Enjoy your aquarium hobby!