Greetings to the list, and Hi Mike,

Assuming you are using three nine volts in series(and .999 silver wire,
of course), and your generating cell (glass of water) is 8 ozs... Let me
suggest a couple of things that may help your method work. 
1) no saline
2) move the wires about 1/8" apart
3) filter the solution every 15 minutes (coffee filter should work well
   enough for your purposes)
4) run at least 4 fifteen minute periods
5) when you have finished, filter one last time (coffee filter), then add
1/2 oz. of dist water containing 5 drops of hydrogen peroxide (3%).
Stir and filter it through your charcoal filter, dilute with dist. water.
Let your color be your guide. :)

Will be waiting to see how it worked. :)

Good Luck and ...

God Bless,

Scott


###############################################################################
John 1:1-  "In the beginning was the Word, and the Word was with God, and
the Word was God. 2 The same was in the beginning with God. 14 And the
Word was made flesh, and dwelt among us, (and we beheld his glory, the
glory as of the only begotten of the Father, full of grace and truth."