For qualitative observations, the elodea in the control flask is mostly dead. More algae cover the walls of the flask, obscuring the water and preventing some of the sunlight from coming through. The 2 pond snails that were added to the control flask are also dead. In contrast, the elodea in the experimental flask is rooted and is thriving within the ecosystem. Because the algae were not added to the experimental ecoflask, the water remains clearer than the control flask. We suspect that it is the algae in the control flask that is causing the death of the elodea, because of the lack of sunlight penetrating through the water. The decaying mass may allow the population of scavengers in the flask to rise. In the future, we will have to keep the pyramid of energy in mind as the control and the experimental flasks each take different turn of events.
An unpredicted event was the growth of new plants in the flasks. The duckweed in the experimental flask is increasing. This was surprising as the levels of dissolved oxygen were constantly being lowered in both flasks. To understand this, we will have to take other requirements for sustaining life into consideration.
We again ran the pH test and the dissolved oxygen test. The control flask had a pH level of 8.0 and a dissolved oxygen level of 5.09 mg/L. The experimental flask had a pH level of 7.59 and a dissolved oxygen level of 3.5 mg/L. We also tested the phosphate level in the control and the experimental flasks. The control flask had a phosphate level of 0.50 and the experimental flask had a phosphate level of 0.55.
The pH levels of both the control and the experimental flasks were within the acceptable range for freshwater environments, which is between 6.5 and 9.5. From the previous test, the pH level has lowered in both flasks. Before, the pH levels were almost too high; now, they're well within the range. The pH levels does not seem to correctly match the health of the ecoflask, because even though they are comfortably within the acceptable range, the control flask still seems to be dying.
The dissolved oxygen levels, however, were far lower than the acceptable range, which is between 9.1 mg/L and 11.3 mg/L. The dissolved oxygen levels in both flasks have also decreased from the previous test. This means that the producers are dying and are not photosynthesizing enough. The dissolved oxygen levels correspond somewhat with the overall health of the flasks. The low levels of oxygen account for the deaths of the elodea and other organisms in the control flask.
The results of the phosphate tests suggest little difference between the control and the experimental flasks. Both flasks had extremely low levels of oxygen, yet experienced some plant growth. We're trying to correlate this phenomenon with the phosphate levels.
Our goal in this ecoflask project is not necessarily to achieve homeostasis, but to figure what would lead to it and what wouldn't. A quality of a good scientist is patient endurance. Although the ecoflasks are dying now and may never revive, these failures can lead to good things. Therefore, we should continue the experiment even more craving for knowledge, rather than being discouraged.
