Sconedesmus dimorphus are a unicellular algae that can be be grown to producce oil for use in bioluels. A research,group is interested in determining if using runoff water from a dairy facility can efficeintly grow the algae cultures while removeing potentially hazardous levels of nitrate and phosphate from the waste water. The chemistry team plans to measure the concentation of five ions (ammonium, nitrite, nitrate, phosphate, and chloride) in the waster water as a function of the time that the water spends circulating in the algae reactor: Identify the dependent, independent, and confounding variables in the experiment being conducted by the group of chemists