The 3-day API WEEKEND PYRAMID FISH FEEDER contains food pellets that are released slowly as the pyramid dissolves. It is made with superior ingredients to feed all tropical, coldwater and marine aquarium fish while you’re away for up to three days, making this automatic feeder ideal for long weekends and holidays. It includes natural ingredients to meet nutritional requirements of all aquarium fish. One pyramid feeds 15-20 average-sized fish in a 37-liter aquarium for up to three days