You've heard of it, but what is borax? Borax is a compound made from the elements boron and sodium. Also known as sodium borate, sodium tetra borate, or disodium tetra borate, borax is a white powder that dissolves easily in water. It has a wide variety of household, chemical and industrial uses. In homes, it is most often found in detergents and cosmetics, as well as in swimming pool chemicals, where it is used as a buffering agent. Borax or boric acid may also be added to soil as a fertilizer, since boron is an important element in the process that allows plants to use calcium.
Borax has been used in pottery since the Middle Ages, when experiments in glazing revealed that borax could be mixed with elements like copper, manganese and cobalt to produce colored glazes and colored borosilicate glass. Later users of borax in ceramics found that it improved the fit of glaze on green ware and bisque. Borax is still an important part of ceramics and glassware making today, along with its multitude of other uses.
In home swimming pools, borax is frequently used to raise the pH of pool water in order to prevent algae and bacteria growth. It is often favored over sodium carbonate, or soda ash, for raising the alkalinity of pool water. In pools with regular algae growths, adding borax can help slow the rate of chlorine use by preventing algae from growing, thus reducing the need for additional chlorine to kill algae blooms. When using borax in a swimming pool, it is important to add muriatic acid as well in order to control the pool's total alkalinity. Since borax can cause digestive problems in dogs, including vomiting and diarrhea, adding large amounts of borax to a pool may also harm dogs that have a habit of drinking from the pool. Borax also softens pool water, improving its overall quality.