This activity examines the water quality of 3 different saltwater aquariums (control variables of volume, light and temperature) with different amounts of dead fish in them (differing amounts of decomposing biomass, and the biological oxygen demand, BOD, created by increased decomposer populations). Over a 22-day trial, the quantities, levels, of dissolved oxygen, DO, and dissolved carbon dioxide, DIC, and pH levels are collected. The students graph the data, analyze trends and patterns and answ