Aquatic plants like Hydrocleys nymphoides, Iris pseudacorus, Saururus chinensis, and Hydrilla verticillata can help clean up polluted water by removing nitrogen and phosphorus. In a study, these plants were grown together in different combinations and tested in eutrophic water conditions. The plants were able to thrive in the polluted water and remove up to 53% of nitrogen and 42% of phosphorus. Some plant combinations were more effective at removing pollutants than others, with Hydrilla verticillata being the best at removing phosphorus. These findings suggest that using these aquatic plants in city water bodies can help improve water quality.