I have been looking into bioremedation techniques to help reduce the amount of nutrients in and flowing into my small 1/4 pond. My water shed contains farm land and park land (soccer fields). I have installed aeration recently and do see improvement (less fil algae). However I still have a bad watermeal and duckweed problem. From what I have read, phosphorus is responsible for this problem. I have planted the strip of land (15 by 75ft ) that the runoff flows through with willows and miscanthis grass, hoping to absorb some of the nutrients before they reach my pond. Are there any other plants that are better for this? It dries out pretty good in most summers. I have planted P. cordata (pickerel weed?) along the edges of the pond. I have recently seen a report that describes a technique called a Periphyton Filter. It is basically a raceway with periphton algae growing in it.The algae removes the phosphorus and the algae is harvested periodically. Does anybody have any experience in operating or building a system such has this. I know that the Aqua mats are based on a similar idea but since the algae is not actually harvested or removed from the pond, are not the nutrients still there when the algae dies? Any suggestions? Thanks kevin