My distilled water is below 3 on my Hanna meter (typically 2) that measures conductivity. So if yours is 0 your water is so pure it won't conduct electricity. Pour a little silver from a finished batch in, to get the current up a little in the beginning. After the current reaches 1 mA the silver puppy won't let it go higher due to the current limiting circuit.
Take a papper towel and wipe off the electrodes every couple hours. I generally don't do this unless I'm making a large amount.
Also. I think your meter may be off. My Silver Puppy takes about 4 hours with a 15 ounce mason jar. The result is around 20 PPM.
If your silver is a little yellow it is probably 20 PPM or more.