Leaf netting is great for keeping out leaves, but it also keeps out the great blue heron. In the fall when the plants are dying back, the fish do not have the normal plant cover and can be easily spotted by the big bird. We reccommend keeping the pond net on the pond until early spring to keep the bird at bay. We have pond tents that help keep the net off of the water and prevents the weight of the leaves from pulling the net into the water. Netting and tents are in stock at the store.