As long as you don't overdose, but DO dose as frequently as the label states, the HEDP should hang onto the metals. Keep in mind that it does NOT remove the metals; it just keeps them in the water.

To remove them, you have to use the CuLator; OR precipitate them with alum or polyaluminum chloride, and then vacuum them out, OR use calcium + high pH + high chlorine to get them to filter out -- and then backwash them off the filter.

The HEDP is buying time, but you need time, right now.