Proper Salt Water Conditions for Aquariums

Marine fish and invertebrates, such as crabs and corals, have evolved in a stable environment. The water conditions within a saltwater aquarium need to therefore be not only suitable, but must remain stable as well. Marine fish and invertebrate creatures are dependent on correct specific gravity, temperature and pH. Sea water animals that are housed in water that does not meet their requirements become easily stressed, and as their immune system becomes impaired, they become predisposed to disease.

  1. Specific Gravity

    • Salinity is a measurement of the amount of salts and other solids that are dissolved in seawater and is expressed as parts per thousand. The actual concentrations of salts are difficult to measure, and marine hobbyists therefore gauge salinity indirectly by measuring specific gravity. Specific gravity is affected in a predictable manner as the salt concentration changes and there is a corresponding specific gravity for each measurement of salinity. Aquarists use a hydrometer to measure specific gravity.

    Temperature

    • Tropical saltwater fish and invertebrates require warm water in which to live. The metabolic rate of both fish and invertebrates is geared to the water temperature in which they are kept. Metabolic rate will slow down and the important life processes become impeded if marine creatures are housed in water that is colder than they require. The aquarium water temperature for tropical marine creatures should be in the region of 77 to 83 degrees. Fluctuating water temperatures stress these animals and cause them to become ill.

    pH Concentration

    • The pH is a measure of the acidity or alkalinity of water. This measurement is represented by a unitless number, which is based on a scale ranging from 1.0 to 14.0. The lower numbers reflect an acidic condition and the higher numbers reflect an alkaline situation, with 7.0 being neutral. The saltwater aquarium should have a pH that remains stable, between 8.1 and 8.3. Marine hobbyists measure the pH of their aquarium water by using a test kit designed for saltwater use. The pH of water in a saltwater aquarium typically drops on a continual basis, due to the metabolic waste from both fish and invertebrate animals. Buffer solutions are available to correct the pH of water, as required.

    Alkalinity

    • Alkalinity represents the sum of negative ions that are required to neutralize the hydrogen ions after acid has been added to water. Two of these important ions, are carbonate and bicarbonate. They are both termed primary buffers and function to maintain a constant pH through suppressing shifts in hydrogen iron concentration. Alkalinity invariably decreases in saltwater aquariums due to the organic acids that are produced by the marine creatures.