Pond Care Algaefix API has been an industry leader in fish care, nutrition, treatments, testing and pond products for over 50 years, giving them a keen insight into your aquarium and its needs - making them the clear choice for fish enthusiasts around the world. APIs Pond Algaefix works to effectively control many types of green or green water algae, string or hair algae, and blanketweed in ponds that contain live plants. The result is clean and clear water gardens and ornamental ponds - even those with plants!