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Graphing Water Quality Data

    Directions for Graphing Water      Quality
     Samples of Water Quality Graphs

Pollutant and Water Quality     Information
     Dissolved Oxygen
     Fecal Coliform
     Methyl-t-betyl Ether
     Turbidity & Sedimentation

Water Testing
     Fecal Coliform
     Dissolved Oxygen
     Company Websites


How to test for pH

According to the state of North Carolina, a pH within the range of 6.0 to 9.0 is considered normal. However pH levels in healthy waters usually range between 6.2 and 6.8.


Using indicators
• which are materials that are specifically designed to change color when exposed to different pH values
• the color of a wetted sample paper is matched to a color on a color chard to infer a pH value
• pH paper is available for narrow ranges (3.0 to 5.5) (4.5 - 7.5) (6 – 8) and also wide ranges (1-11)
• pH paper is typically used for preliminary and small volume measuring,

Using a Colorimeter
• the device uses a vial filled with an appropriate volume of sample to which a reagent is added
• as the reagent is added a color change takes place
• the color is then compared to a color wheel or spectral standard to determine the pH value

Colorimeters are much more expensive and also can conduct multiple other tests, if you are looking for the simplest way to test for pH then using paper indicators are the best.

HACH company product numbers for testing pH are below

pH paper indicators
• Product #: 2601300
• Product #: 39133
• Product #: 38533
• Product #: 37333

• DR/890 Portable Colorimeter (Product #: 4847000)
• DR/850 Portable Colorimeter (Product #: 4845000)
• DR/820 Portable Colorimeter (Product #: 4844000 )