I have a Silver Puppy with a stiring system. It produces clear 20 + PPM on auto. Their is always oxide on the silver rods that falls off into the batch. I could let it sit and then pour off the top leaving the settled out part on the bottom. If I did that I would be wasting a little bit of the best Colloidal Silver in the world. So I filter it instead. If your silver is worth squat it shouldn't effect the PPM one bit, plus your filtering out some of the impurities that may be still suspended in the water.