Lab report: aquaponics 2017
Lab Report: Aquaponics 2017
Design
*Our group started by determining our type of plants, and what kind of fish we would use.
Conclusion and Evaluation
Design
*Our group started by determining our type of plants, and what kind of fish we would use.
- Defining the problem: An aquaponics system is growing plants from fish waste, and recycling the leftover water from the plants back to the fish. The plants, however, depend on mass amount of waste from the fish to support their growth. The fish food that we will give our fish will have a certain amount of protein in it. Our question is whether or not the amount of protein in the fish food will affect the height, leaves, and colour of the plants, and how well the plants will grow from the fish waste, or whether or not the plants will die because of the amount of protein in the fish food.
- Controlling the variables: Our independent variables are the plants watered with the crude protein and waste filled water and the plants watered with regular tap water from the school sink. The dependent variable is the measured height of the plants. The controlled variables are the amounts of water given to the plants, the duration that the day light is on, the amount of food given to the fish, and the frequency of when we cleaned out the tank.
- Developing a method for collection of data: Plant and fish growth will be measured with a tape measure and recorded in separate tables before being converted into graphs after every two weeks. Conditional changes with the tank, goldfish diet, or growth will be recorded on a daily basis before also being converted into graphs. Temperature and pH will also be recorded if there are any necessary changes with them.
- Recording (quantitative data, qualitative data, units and uncertainties): We recorded the heights of the the Spearmint (Mentha spicata), Basil (Ocimum basilicum), and Cilantro (Coriand sativum) by measuring the length of the stem from root to tip in cm. We repeated this process for every plant, sprouted or not, every 2-5 days. We also measured the level of nitrate, nitrite, and ammonia in the tank at least once a week. We did this with testing strips where it would give you a level 1-7 or 1-5 to access the amount in the water.
- Processing (quantitative data): Throughout our aquaponics experiment, while taking the height of the plants, we processed the difference between the height of the soil plants and aquaponics plants. This helped us determine whether our hypothesis was right or wrong, and what we could do in the future to correct our hypothesis to be correct, or how we could not fix the aquaponics container, and had to accept that our hypothesis was wrong. We also throughout the experiment, measured the nitrogen levels in the tank (NO3, NH4, NO2) and the pH in the tank. This helped us determine what went wrong in the tank if something did end up happening, and how we could correct those levels to be at a neutral level. We did determine that our pH levels were at a continuous average range of 5.0-5.5, and all nitrogen levels varied throughout the experiment.
- Presenting: look below.
Conclusion and Evaluation
- Concluding (With justification, based on reasonable interpretation of data): Our conclusion was that the plants that grew in the tap water container, grew more fit, and gained more height than those in the aquaponics container. Our hypothesis was wrong; the plants were watered at the same time every few days (2-5 days), were grown in the same amount of artificial daylight, and we did grow the same plants in the same spots in each container. Our plants in the tap water container had a significantly higher growth rate than those in the aquaponics container.
- Evaluating Procedure (Weaknesses and Limitations): In our aquaponics tank, we had holes coming out of the bottom of the container to drip the water from the plants back into the tank, to re-circulate water. This was a mistake on the group’s part because one container’s water was drained out before it was all absorbed, and the other tank (the control group, the tap water group) had much more water to absorb, which could have pushed the growth rate of the plants in the tap water group. Our light situation also could have improved. We had a single lamp that had a 40W daylight in it. We feel that this light also controlled how well our plants grew, and how this light was also a huge source of resources for the plants. We also had trouble controlling our pH in the tank, which could have affected the amount of secretion from the fish, including how their waste was used in the plants, and how the pH of their waste could have affected plant growth also.
- Improving investigation (Realistic Improvements of Defined Weaknesses and Limitations): For our containers, we should have either pushed holes in both (which is not probable because tap water is chlorinated, which could kill the fish) or measured out water equally to have the aquaponics have a little more water (since the some of the water dripped out of holes in the bottom). For our lighting situation, all we would have need were two desk lamps to equal out the light, or have a longer lamp that we cover both plant containers in equal coverage. To average out our pH, we are still not sure why the water was such a low pH (5.0 on average), but we do believe that it had to do with the school’s water system. To average out our pH to a neutral 7.0, we should have cleaned out our tank more often as we cleaned it very rarely (cleaning it meaning that we replaced at least ⅓-⅔ of the water in the tank with clean, dechlorinated water), or scooped any soggy, uneaten food that was left in the tank that caused algae to grow.
Presenting