While APT is designed to reduce algae occurrence, it is not an algicide and will not by itself remove algae. It works by enabling plants to successfully outcompete algae, the same way that trees in a forest outcompete weeds for light and nutrients. It also smartly controls the amount of nutrients that trigger algae, while providing enough for healthy plant growth. We suggest reviewing the causes of algae, and the detailed guides on managing specific types of algae.