The third part of our project we would like to tell you all about is dissolved oxygen. If you are anything like me you might be thinking: “Huh? How do you measure oxygen in water?” To which I would lead you to the wonderful explanation below. Keep reading to figure out more about how the heck we manage to measure it.
Another one of our team members, Flavia, explains dissolved oxygen, how it effects our oysters and how we go about measuring it.
Why is it important?
“The dissolved oxygen level in a tank is one of the most important indicators of water quality. Oxygen dissolves in the water through our aerator and occasional air movements on the surface of the tank. Colder water holds more oxygen than warm water, and salt water can hold less oxygen than salt water. Without enough oxygen in their tanks, the oysters can die.”
How do we measure it?
Materials
- Dissolved Oxygen Measurement Kit that keeps the testing kit away from sunlight which can ruin the testing kit’s accuracy.
- Red solo cup to take a dip of water at a time from each tank to measure dissolved oxygen levels.
- Graduated cylinder filled with 25 ml of water from solo cup
- Two ampoules filled with indicator liquid.
- Dissolved Oxygen Color Chart to compare the color of the ampoule to the closest color on the chart.
Method
- Fill red solo cup with water from control tank
- Fill graduated cylinder with 25 mL of water from the red solo cup
- Take one ampoule and place the side with the indicator liquid into the little divots at the bottom of the graduated cylinder, pushing the tip of the ampoule from the top until it breaks and fills with water.
- Remove the ampoule from the graduated cylinder and flip it four times
- Leave the ampoule upright for two minutes.
- Take note of the color of the ampoule and compare it to the colors on the Color Chart. If the ampoule’s color is between two colors, you can say the dissolved oxygen level is between the two numbers, such as if it’s between 6 and 8, it might be a 7. Measurements are in parts per million (ppm).
- Repeat above steps with the experimental tank making sure to sanitize anything that touched the control water tank in order to ensure accurate results.
- Place materials back where they came from, making sure to put the Dissolved Oxygen Measurement Kit away from sunlight or other sources of light.
