Silicon and phosphorus 

Si and P take place in nature only in fully oxidized forms (SiO₂ and silicates, phosphates), that are involatile and comprise low solubility in natural waters. Phosphorus is one of the most significant elements of life and within aquatic environments the one that is frequently in shortest supply. Pollution through soluble polyphosphates (example from detergents) can critically upset the ecological balance of lakes, leading to not controlled growth of algae and depletion within the dissolved oxygen.