Algae and Blanket Weed suffocate garden ponds due to their fast growth during the early spring period. Blanket weed can grow up to a foot a day. With a lack of plant competition for the pond nutrients and light, they quickly take over, posing a risk to aquatic animals. One method to control these algal blooms is to provide competition for the light and nutrients they need. Water Lilies provide large areas of shade and prevent the light penetrating the water surface. Oxygenating plants take away the carbon dioxide that the algae need to grow and convert it to oxygen. This, in turn, helps algae-eating animals to thrive, such as water snails, tadpoles and many species of larvae.