Phosphates are particularly important for the growth and development of plant roots, and hence are one of the most common fertilizers used in agriculture.
Zinc is normally introduced into drinking water through industrial effluents, especially due to dezincification of brass and deterioration of galvanized iron.
Small quantities of silver are bacteriostatic or bactericidal. As a result, it is at times used in disinfection of pools and spas, as well as in water filters.