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.
In swimming pools, calcium carbonate is normally added during routine pool water maintenance to increase pH, increase calcium hardness, maintain total alkalinity, and offset the acidic properties of disinfecting agents like chlorine or bromine.