Quote Originally Posted by thilbert

> I googled EDTA and it turns out that the main component of "Metal Out",
> mentioned previously, is EDTA with a twist, MSDS lists its chemical name
> as: Ethylenediaminetraacetric Acid Tetresodium Salt. Salt being the
> difference.



Tim
Some thoughts:

EDTA is a the chelating agent that is used as the tritrant in the calcium hardness test (reagent #3). It complexes with the calcium (or metals) in the solution. The complex is a large molecule but to filter it out the question becomes how fine a filter medium do you need. Some type of millipore filter medium might work.

There is also a material called poly filter
( http://www.poly-bio-marine.com/ )
that is used in water purification and aquarium use that is very efficient at removing copper. Perhaps this might be an easier experiement to try. Filtration through active carbon first would help remove the chlorine which might interact with it. I have much first hand experience with using this product to remove copper from aquarium water when it has been used for treatment of ick.The main problem would most likely be cost since quite a lot would probably be required to filter a pool! might be an intersting route to try!