ok so i built a cell and have been running it at 8volts 4.5 amps using tap water and baking soda. i know the discoloration is possibly due to the electrolyte. the thing is the center of the plates are black and all around the edges there is no discoloration. if i ever figure out how to post a pic i will. thoughts on this, the plates are thin and possibly maybe they are closer in the middle? or the edges?