Try varying the distance between or or one block deeper than the other that is one way to adjust I,.through the resistance of the cell it self. You may also want to try a peice of stainless steel wire or ??? for your Cathode. Did you look for the 5v/25A through the pin connector? the case it ground just start probing until you ID all the 5v pins then try them out. I also know that surface area of each is important. Do you know of visser's site reguarding chlorate/perchlorate production? He has done all the Math and is really quite good in his information.http://huizen.dds.nl/~wfvisser/EN/chlorate_EN.html
Try that I'll see if I can find some more of those link's.My Email is firstname.lastname@example.org
I can send you a couple of files if you have an adress.