SILICIC ACID is a collective name for silicon-containing compounds in water. The acid owes its name to the Latin word origin for silicon, because “silex” means, as you already guessed it: “pebble.” Even though SILICIC ACID is present as a form of silicon in the earth's crust and thus in almost all bodies of water, the removal of silicic acid is a challenge for water treatment: Undissociated, i.e. not split, SILICIC ACID can very easily get into the product water and leave behind deposits that are difficult to remove.