There are several posts in the Metals forum by people who have made homemade filters and run their fill water through to filter out the metals. The theory is that if you run the water past a high chlorine source right before it hits the filter, it will cause the metals to drop out on to the filter. The ones who have posted about it in this forum all have had varying levels of success with it. Might use the Google search link in Watermom's sig to search the forum for metal filters...