Procedure for Testing Phosphate in Water

Phosphates are chemical compounds that contain phosphorus, a natural element. Phosphorus is necessary for normal growth in plants and animals. Many household items have phosphates in them, such as fertilizer, detergents and sewage, and contaminate water with high levels of phosphate that promote excessive algal growth, a water quality hazard (http://extoxnet.orst.edu/faqs/safedrink/phos.htm). Testing levels of phosphate is necessary to mitigate the overgrowth of algae in waters including pools, lakes, and ponds.

Testing Options

• There are several different methods of testing phosphate levels. Many people prefer to use sticks that indicate the level of phosphates in the water by turning color, while others choose an indicator solution dropped into a small sample of the water that changes color according to the amount of phosphates in the water. Whatever kind of kit one chooses, the steps are quite similar, after the kit is purchased (read the directions on the kit, as well).

Testing Procedure

• Order a kit that fits your needs (consider what you are measuring -- pool, lake, pond). Once you receive the kit, read the instructions. Use the testing apparatus, be it a stick that you emerge in the water for about 30 seconds, or a glass that you draw some water from and drop indicator solution into. Use the guide in the kit to discover what colors indicate safe/unsafe levels of phosphorus. If levels are safe -- congratuations. Check back with the water source often. If the water levels are not safe, treat the water according to directions in the kit or by treating the water with a base (alkaline) from the lime or limestone family to neutralize the phosphates (http://www.sponwater.com/news.asp?news_id=40). Normal values for most freshwater systems are 6.5-8.5. (http://www.ncsu.edu/sciencejunction/depot/experiments/water/lamotte.html).