Waste not want not MFC

[deleted-149681]

I am making a Microbial Fuel Cell and testing the effects of various waste waters on the output of the cell. In the procedure, it states "Collect some of the stream water in the cleaned 1-gallon jug" and "Make a conductive salt solution using the water sample from the 1-gallon jug. Measure out 12 cups of stream water into the large bowl. Add 6 Tbsp. of salt to the bowl and stir with a spoon until the salt has been dissolved. Fill the cathodes of the three fuel cell pairs with the salt solution.." What is the importance of the water being from a stream? Can I use tap water to make the conductive liquid that is put in the cathode? Also, how long do you think I should run the experiment and how often should I measure the output. Thank You

[deleted-141593]

Please see my reply here: https://www.sciencebuddies.org/science- ... 28&t=12263