Zoo Med Laboratories AZMBB5 Plankton Banquet Block Feeder Mini Great for bottom feeders Lasts 3-4 days For fresh and saltwater Zoo Med Laboratories plankton Banquet Block Feeder Zoo Meds Plankton Banquet time release feeding blocks last 3 to 14 days, depending on block size Original Banquet blocks are also very useful for small fry which do best when constantly feeding Original Banquet blocks are also very useful for small fry which do best when constantly feeding