A study was done to see how three water plants can clean up polluted water in a lab setting. The plants were Iris sanguinea, Acorus calamus, and Iris pseudacorus. They were put in water that was like what you'd find in a reservoir with too many nutrients. After 28 days, the plants removed a lot of the nitrogen and phosphorus in the water. Iris pseudacorus was the best at cleaning up, especially for nitrate nitrogen. The plants worked best at first and then slowed down over time. Nitrate nitrogen was cleaned up the most consistently, while total nitrogen and ammonium nitrogen were cleaned up best in the beginning, and total phosphorus was cleaned up best in the first few weeks.