My tank, and only reef experience, has been set-up about a year and a half so I have no experience on this issue.
It is worth keeping in mind that no two tanks are the same and so we can only talk in generalities. Rob Toonen has a tank that is going strong after 16 years.
For example, the source of metals could be leaching from the LR in your friends case, but that doesn't mean, even if true, that all tanks with LR will suffer the same fate.
Great topic, as it effects the vast majority of reefers, including yours truly.
