In the home aquarium world, we plant desirable plants that use the excess nutrients in order to choke out the undesirable plants. This can also be used in the pond world on a much larger scale.
Our pond isn't old enough to be affected just yet, but I'm already taking efforts by planting pickerel weed and water irises around the margins. These plants spread slowly compared to other types and are beneficial in attracting honey bees and dragonflies.
