Pond Boss Forums AQUATIC VEGETATION Identifying plants brown scummy lines on top of water

Have the same thing in my pond. Really shows up when the kids go swimming, or if I redig the pond. At first I thought it was oil or some other petroleum product in the ground. Spent several hundred dollars on booms to collect and soak up the stuff. But to my surprise, it did not soak up any of it, it did contain it and allow me and my boy to scoop it out with buckets. When it rains it dissipates and only part of it shows back up. Eventually the stuff in my pond goes away until someone distubs it and it rises to the surface again, seems a lot worse in the summer.