think about making a model is made a model of freshwater ecosystem he put a leader of durable on the bottom of a large clear plastic containers the algal a hero of sand is poured water in the tank the strand would not stay in place it cloud the the water he had had to start again he put paper over the sun and for the water in his settings plant and rock on the top of the paper when he saw what had he and rocks into that he added decisions male right away the fish did not look will he took them out and put them back in his other aquarium in let the water heat for a week we added the fish and snails david well david well what mistake did jeff make it more​