I just returned from Ohio and have made some decisions about the pond. I found out it is only 14 years old and is not silted. It only is 4 feet deep and was built collect run off from a strip mine operation. I am going to raise the water level about 5 feet by using 12 inch plastic clavert pipe inside the exsisting 24 inch stand pipe. Top of the dam is 9 feet above the current water level. My only concern is one of the springs feeding pond has a rust that sticks to the plants and rocks where it flows in. Do I need to deal with it? How?