Penn Plax Pro-Balance Squid Shape Vacation Feeding Block - 1 Per Blister Card Color of feeding block may vary (white or orange) Contains Pro Balance high quality fish food. Time-release formula can feed your 10-15 gallon aquarium for up to 10 days. Contains fish favorites like shimp & daphnia with added vitamins & minerals. Perfect for cichlids, gouramis, parrot fish and other similar size fish.