The Constituents Of Seawater
December 19, 2008 · Print This Article
The seas and oceans cover the majority of the planet surface. Within those seas the wild reefs have grown and all of their needs are met, be that calcium or whatever. The life on the wild reef has had a very long time to adapt to the sea, which is considered to be stable.
Some of these life forms end up in the home marine aquarium. With the natural seas being so stable it follows that for success the conditions on the wild reef should be duplicated as near as possible, and conditions provided that successfully permit life to function and be healthy.
Seawater quality is the number one on the list of ‘must haves’ for success so it follows that the seawater used should be as close as possible in make-up to the natural kind. In much earlier days aquarists would obtain some constituents – not all of them by any means – from a chemist and mix up a brew. Livestock existed in this fairly well for a while but trouble usually appeared. Nowadays there are many high quality dry salt mixes available which the manufacturers state equals the natural type. Be that as it may, the appearance of these dry salt mixes has brought the successful maintenance of a marine system within the reach of every aspiring aquarist provided the interest in the hobby is maintained and the requisite maintenance is done.
Seawater is a mix of many things, some of them present in major amounts, others in trace amounts, and more with a very tiny presence. So for the benefit of anyone interested there follows a list of the make-up of seawater. There is clearly no requirement of any kind for an aquarist to know them but as said it may be of interest. It could also be of use for aquarists who wish to maintain natural levels of important parts such as calcium etc.
Major Elements. (All measurements in mg/l)
|
Chlorine |
18880 |
|
Sodium |
10770 |
|
Magnesium |
1290 |
|
Sulphur |
884 |
|
Calcium |
412.1 |
|
Potassium |
399 |
|
Bromine |
67.3 |
|
Carbon |
28 |
|
Nitrogen |
15 |
|
Strontium |
7.9 |
|
Boron |
4.5 |
|
Silicon |
2 |
|
Fluorine |
1.3 |
Trace Elements. (All measurements in ug/l)
|
Lithium |
180 |
|
Rubidium |
120 |
|
Iodine |
60 |
|
Phosphorus |
60 |
|
Molybdenum |
10 |
|
Zinc |
4.9 |
|
Argon |
4.3 |
|
Arsenic |
3.7 |
|
Uranium |
3.2 |
|
Vanadium |
2.5 |
|
Aluminium |
2 |
|
Barium |
2 |
|
Iron |
2 |
|
Nickel |
1.7 |
|
Titanium |
1 |
|
Copper |
0.5 |
|
Cesium |
0.4 |
|
Chromium |
0.3 |
|
Antimony |
0.24 |
|
Manganese |
0.2 |
|
Krypton |
0.2 |
|
Selenium |
0.2 |
|
Neon |
0.12 |
|
Cadmium |
0.1 |
|
Wolfram |
0.1 |
|
Cobalt |
0.05 |
|
Germanium |
0.05 |
|
Xenon |
0.05 |
|
Silver |
0.04 |
|
Gallium |
0.03 |
|
Lead |
0.03 |
|
Zirconium |
0.03 |
|
Bismuth |
0.02 |
|
Mercury |
0.02 |
|
Niobium |
0.01 |
|
Thallium |
0.01 |
|
Thorium |
0.01 |
|
Tin |
0.01 |
|
Hafnium |
0.007 |
|
Helium |
0.0068 |
|
Beryllium |
0.0056 |
|
Gold |
0.004 |
|
Rhenium |
0.004 |
|
Lanthanum |
0.003 |
|
Neodymium |
0.003 |
|
Tantalum |
0.003 |
|
Yttrium |
0.0013 |
|
Cerium |
0.001 |
|
Dysprosium |
0.0009 |
|
Erbium |
0.0008 |
|
Ytterbium |
0.0008 |
|
Gadolinium |
0.0007 |
|
Praseodymium |
0.0006 |
|
Scandium |
0.0006 |
|
Holmium |
0.0002 |
|
Lutetium |
0.0002 |
|
Thorium |
0.0002 |
|
Indium |
0.0001 |
|
Terbium |
0.0001 |
|
Samarium |
0.00005 |
|
Europium |
0.00001 |
|
Radium |
0. 00000007 |
|
Protactinium |
0. 00000005 |
|
Radon |
0. 000000000006 |
Constituents with a tiny presence.
|
Technetium |
|
Ruthenium |
|
Rhodium |
|
Palladium |
|
Osmium |
|
Iridium |
|
Platinum |
|
Astatine |
|
Francium |
|
Actinium |
(Reference: ‘Baensch Marine Atlas’. Helmut Debelius & Hans A. Baensch)






Sea water is certainly a more than just h20! It certainly underlines the need to be vigilant in your water testing. Saltwater master test kits usually contain tests for ammonia, nitrite, nitrate, pH and sometimes alkalinity. It is also good to have a Hydrometer handy to check your salt levels
Certainly is! It’s the number one ‘high quality’ requirement, closely followed – in a reef system anyway – by lighting.
Johns last blog post..Is It Confusion That Prevents People From Starting Or Something Else?
Although the vast majority of seawater has a salinity of between 3.1% and 3.8%, seawater is not uniformly saline throughout the world. Where mixing occurs with fresh water runoff from river mouths or near melting glaciers, seawater can be substantially less saline. The most saline open sea is the Red Sea, where high rates of evaporation, low precipitation and river inflow, and confined circulation result in unusually salty water. The salinity in isolated bodies of water (for example, the Dead Sea) can be considerably greater still.