Captive guppies are not picky eaters, and they do enjoy eating algae. Guppies found in the wild have slightly altered diets but also consume algae.
Captive guppies require a mixture of foods, such as fish flakes, brine shrimp, mosquito larvae and blood worms. Algae should not be considered a substantial form of nutrition for tank guppies. While it is not necessary, guppies can also consume algae wafers. However, it is best to break algae wafers into pieces before putting them in the tank. According to PawNation, wild guppies eat a variety of foods, such as zooplankton, bug larvae and benthic algae.