Artificial seawater


Artificial seawater is a mixture of dissolved mineral salts that simulates seawater. Artificial seawater is primarily used in marine biology and in marine and reef aquaria, and allows the easy preparation of media appropriate for marine organisms. From a scientific perspective, artificial seawater has the advantage of reproducibility over natural seawater since it is a standardized formula. Synthetic seawater is also known as artificial seawater and substitute ocean water.

Example

The tables below present an example of an artificial seawater preparation devised by Kester, Duedall, Connors and Pytkowicz. The recipe consists of two lists of mineral salts, the first of anhydrous salts that can be weighed out, the second of hydrous salts that should be added to the artificial seawater as a solution.

SaltMolecular weightg kg−1 solution
Sodium chloride 58.4423.926
Sodium sulfate 142.044.008
Potassium chloride 74.560.677
Sodium bicarbonate 84.000.196
Potassium bromide 119.010.098
Boric acid 61.830.026
Sodium fluoride 41.990.003

SaltMolecular weightmol kg−1 solution
Magnesium chloride 203.330.05327
Calcium chloride 147.030.01033
Strontium chloride 266.640.00009


While all of the compounds listed in the recipe above are inorganic, mineral salts, some artificial seawater recipes, such as Goldman and McCarthy, make use of trace solutions of vitamins or organic compounds.

Standard

The International Standard for making Artificial Seawater can be found at ASTM International. The current standard is named ASTM D1141-98 and describes the standard practice for the preparation of substitute ocean water.

Uses

There are various applications for ASTM D1141-98 synthetic seawater including corrosion studies, ocean instrument calibration and chemical processing. Typically, laboratory grade water is used when making synthetic salts