The technical term for this chemical is sodium carbonate. It is a white, crystalline substance that is stable in the air, although it is considered hygroscopic. This means that it absorbs moisture from the atmosphere, so it should be stored in airtight containers. It is odorless and produces an alkaline solution when mixed with water. As the product pH Plus, sodium carbonate is classified as a water softener. However, unlike other varieties of this chemical, it is harmful so it should not be used as a treatment for drinking or potable water. This product is used to increase the pH of pools that are at risk of becoming too acidic. Sodium carbonate is toxic to humans and can irritate the skin and eyes. It should also never be ingested in its pure form as it can be hazardous and potentially fatal. Gloves and goggles should be worn when handling this substance.