The only way I've heard of for getting Copper out of a glass tank is with acid baths. Dangerous to say the least. I believe that Edta will only bind with metals that are in solution but since I'm not a chemist I can't say for sure.
If you really want to try it, you might be able to get the EDTA from "Hach". I know a 100 ml bottle of EDTA from Hach, for refills for the test kits , is about $9 - $10 a bottle. If you were looking for quantity or a dry form, (if it comes this way) so you could make your own solution, they might have it. Otherwise maybe Chris or Jerel will pick up on the thread and know the answer and where to get the chemicals.
If you really want to try it, you might be able to get the EDTA from "Hach". I know a 100 ml bottle of EDTA from Hach, for refills for the test kits , is about $9 - $10 a bottle. If you were looking for quantity or a dry form, (if it comes this way) so you could make your own solution, they might have it. Otherwise maybe Chris or Jerel will pick up on the thread and know the answer and where to get the chemicals.