Tetra has been revolutionizing and improving fish nutrition since the company’s birth in Germany in 1951. Since that time, Tetra has developed one of the most comprehensive bodies of fish food knowledge in the world. Never fear traveling and leaving your pet fish while you’re on vacation. Tetra’s Weekend Slow Release Tropical Feeder Fish Food feeds a fish up to 14 days per block. The unique, gel formula is plaster free. Packed with Tetra’s ProCare formula these gel blocks are highly nutritious and will keep your fish full and satisfied for just under a week. Not only are they nutritious the Tetra Weekend Slow Release Food Blocks do not cloud your aquarium’s water. These blocks are best suited for tropical fish and contain the ingredients that your fish needs to stay healthy and full while you and your family are travelling. If the blocks are not fully consumed when you return it is safe to leave them in the aquarium.