Dissolved Oxygen in Water
Publication No. 11954
The amount of dissolved oxygen in a water sample will be found by using the TesTab® color comparison method.
Dissolved oxygen is the amount of gaseous oxygen, O2, dissolved in an aqueous solution. Oxygen enters into the water by aeration, diffusion from air, and as a byproduct of photosynthesis. The concentration of dissolved oxygen is one of the most important indicators of the overall health of a body of water. When bodies of water contain a large amount of oxygen, the quality of the water is generally considered as being good. When the amount of oxygen in water is very low, the pollution level of the water is most likely very high. Water with consistently high levels of dissolved oxygen (6 parts per million or more) typically supports the most diverse biological communities. Water with consistently low dissolved oxygen levels (below 3 parts per million) is extremely stressful to aquatic organisms and may be virtually void of aquatic life or may harbor only a few species adapted to such conditions. Dissolved oxygen levels below 2 parts per million will not support fish life.
Dissolved Oxygen TesTabs®, 30
Dissolved Oxygen Color Comparison Chart
Dissolved oxygen test vial
Dissolved Oxygen TesTabs® contain chemicals that may irritate skin or be harmful if swallowed. The TesTab reagents used in this kit were designed with safety in mind. The single-use, foil-packaged TesTabs are easy to dispense. Store TesTabs in a cool, dry place and only open when ready to use the tablet. A single tablet, either alone or reacted with a sample, is a very low health hazard; however, TesTabs should not be ingested. Wear chemical splash goggles and chemical-resistant gloves. Please review current Safety Data Sheets for additional safety, handling and disposal information.
Please consult your current Flinn Scientific Catalog/Reference Manual for general guidelines and specific procedures, and review all federal, state and local regulations that may apply, before proceeding. In the field, reacted samples may be poured into a container for later treatment. Reacted samples may be flushed down the drain with plenty of water according to Flinn Suggested Disposal Method #26b.
Correlation to Next Generation Science Standards (NGSS)†
Science & Engineering PracticesPlanning and carrying out investigations
Analyzing and interpreting data
Disciplinary Core IdeasMS-ESS3.C: Human Impacts on Earth Systems
HS-ESS3.C: Human Impacts on Earth Systems
Crosscutting ConceptsStability and change
MS-ESS3-3: Apply scientific principles to design a method for monitoring and minimizing a human impact on the environment.