An important note about Mother Natures great plant, Algae. Algae is probably the most important plant on the planet. We would not be here to day without the presence of algae of one form or another. Your water feature should have algae, the algae should be part of a very important biofilm. The right algae in the right place can actually help you keep your pond or water feature clean. Too much algae does cause problems within a closed system such as a pond or water feature, thus the need for algae control.