First step is to identify what type of algae are we dealing with, platonic algae or string algae. Next is choose the appropriate treatment measures. You have many treatment options including the addition of pond plant material to compete with the algae’s food source, add additional beneficial bacteria, add a fish safe algaecide such as Aquascape’s Liquid Algaecide (a phosphate binder). Bonus – We use and recommend the Aquascape Automatic Dosing system. This system adds beneficial bacteria, enzymes and phosphate binders automatically and daily to your pond. Greatly reducing maintenance.