Homebrew PCBs

If you have dark green, you have CuCl.  Pour it into your other tank and 
turn on the bubbler, that's all.  Note: dark GREEN is good, dark BROWN 
needs more air time.

See http://members.optusnet.com.au/~eseychell/PCB/etching_CuCl/ for the 
rest of the chemistry :-)