Zoo Med Laboratories AZMBB3 Giant Banquet Block Feeder 2-Count (Two 1-unit cards) One time-released Giant Original Banquet Block will feed approximately 15-20 average sized aquarium fish for 10 to 14 days Made with high protein micro pellets; great for bottom feeders, fresh or saltwater fish Original Banquet Blocks will not cloud water Do not use this product in fish bowls or aquariums which do not have aeration or filtration