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.
Test and adjust your pool to these levels: Free Chlorine: 1-3 ppm, pH: 7.2 â 7.6, Alkalinity: 80 â 120 ppm and Calcium Hardness: 200 â 400 ppm. Proper water balance in your pool is crucial to keeping clean water and staying algae free.