Answer: Algae is a very bad animal to me. Algae makes up a large group of organisms; it can produce its own food by photosynthesis. It comes in many different colors. Some of the algae can even be toxic to the fish. Algae is excess nutrients, and the sunlight, water temperature, high phosphate, you can write a book about algae. The best thing you can do is just give us a call and we can try to go over all the different types of algae or come out to your property and take a look for you.