Estuarine condition is the saline and tidal conditions occurring due to tidal action and mixing of fresh and salt water in the estuary. When referring to estuarine condition, we are referring to the salinity, sediment, dissolved material, and particulate material of the estuary. In a laboratory, water is often purified to remove all other materials, containing only oxygen and hydrogen atoms. This water is called distilled water. Distilled water does not normally occur in the real world. Water is often diluted with salt, organic, and particulate material. This material can either benefit or cause negative effects in an estuary.