The researchers wanted to see how well two types of plants, Phragmites australis and Eichhornia crassipes, could remove high levels of phosphorus from water. They set up experiments with different phosphorus concentrations and found that both plants were able to remove over 60% of the phosphorus from the water. The plants accumulated the phosphorus in their tissues, with the submerged parts of the leaves storing the most. Both plants were able to grow well even with high phosphorus levels, but Phragmites australis was better at accumulating phosphorus than Eichhornia crassipes. This suggests that Phragmites australis could be a good choice for cleaning up water with high phosphorus levels.