You should take a scrub brush and clean out whatever you are going to use to make the Colloidal Silver . Then take a little bit of the distilled water and clean it again by shaking it in the container. Measure your distillled water with a Hanna meter to see if it's good enough.
I filter my colloid with a paper non bleached filter after it sits for a day. It doesn't drop my PPM any noticeable amount.
If your silver is yellow you may have to get a stiring system.