Ecomare

Silicon is the element from which sand is made, as a non-dissolvable silicon oxide. Silicon in the form of a dissolvable salt (silicates) is considered a nutrient. It is an essential material for animal growth. Nitrogen and phosphate are also nutrients. In contrast with these two materials, the increase in the emission of silicon has been negligible in past decades. Diatoms use the material to build up their siliceous skeletons. Due to the overabundance of nitrogen and phosphate, silicon in fresh and salt water becsme the limiting factor for diatom growth. Now that there is less phosphate, it is phosphate that has become the limiting factor.