Soda ash, also called sodium carbonate or washing soda, is used in many water softeners. This chemical makes the water less acidic, allowing more effective washing with soap. It also increases the sodium level in the water--a health concern for people who limit their sodium intake. This chemical is readily available and inexpensive, making it a popular solution for many people with hard water.
Soda ash is a trade name for sodium carbonate, which is refined from natural mineral deposits or manufactured via a chemical process. This raw material is used in more than just water treatment, including glass making, detergent manufacturing, dyeing, and other processes. It's a more price-stable and less volatile substitute for caustic soda in water softening and is cheaper than potassium salts.
Natural soda ash can be found in dry areas, especially in areas where lakes dry up and refill seasonally. One form of natural sodium carbonate is called natron; it was used by the ancient Egyptians to create mummies. Sodium carbonate has also been found in a volcano in Tanzania and in ultra-alkaline rocks. It is mined in a number of locations, including Wyoming and Kenya.
In hard water, soda ash can reduce the impact of trace elements like magnesium and calcium. This chemical prevents the trace elements from bonding with detergents, making the detergent more effective. Soda ash is often sold in the laundry section of department stores for direct use in washing machines. When added to water with a pH of less than 7, soda ash increases the alkalinity. It can keep water from being as corrosive and reduce the amount of mineral scale that builds up in your pipes.
If you need to limit your sodium intake based on doctor recommendations, don't forget to check your water softener. Water softeners can greatly increase the amount of sodium in your diet. Consider using potassium salts to soften your water instead. It could result in much better health, with minimal changes to your lifestyle. For people not on restricted sodium diets, soda ash water softeners pose little threat.
Although soda ash is less dangerous than caustic soda and other extremely alkaline chemicals, it is still caustic. Wear gloves while handling it and avoid getting soda ash in your eyes or mouth. This chemical is not poisonous but can cause skin and mucus membrane irritation. Goggles may be appropriate if the soda ash has a chance of becoming airborne. If irritation does occur, dab the areas with vinegar to neutralize the chemical, then flush the area with water.