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.
Calcium hardness is the measure of the amount of dissolved calcium found in your pool water. If this particular pool parameter is not right, it can lead to an aggressive pool. Thus causing damage to your pool and mechanical systems. In most cases this part of your swimming pool water chemistry is not tested very often.