Find out what this food is! Boil up a few pieces of spinach leaves until they are soft. Remove from hot water and run under cool water. Place them in the tank and wait for the shark tank behavior to begin! In the video watch for the chunk one guppy tears off and swallows. Guppies are omnivores which means they eat both animal and plant matter. Spinach and other green leafy vegetables like swiss chard are good for them. The plants provide calcium and chlorophyll that they need to stay healthy. Boiled frozen peas with the outer shell removed, then cooled are also enjoyed by guppies. For guppy fry, I squish the inner pea. For larger guppies, I simply toss it in and let them peck at it. I feed greens at least three times a week. Plant material is also a good laxative for many fish.