Salary. The Bureau of Labor Statistics reports that marketing managers in the United States earned an average annual wage of $126,190 as of May 2011. The median wage, or midway point between the lowest and highest salary, was $116,010 per year.
What is TDS. TDS is the total of all dissolved solid matter such as minerals, metals, salts and. contaminants in the water. B. How TDS is Determined. TDS is most often determined in pool and spa water by using a conductivity meter. These. electronic meters measure the waters' ability to conduct an electric current.
Swimming pools that have higher volumes of water contain higher amounts of contaminants. In addition, a pool with a bigger surface area also means there is higher evaporation of pool water and the dissolved chlorine. So the bigger the volume and surface area the higher the amount of chlorine needed.