I would just like to interject here and then we can leave the tap water discussion behind or someone start a new thread on it...
We have to appreciate that we can only suggest what we think is best for a tank or system, that is not the only way to do it though. With regards to tap water, we have reefers on this site who have used tap water for years and have never had any ill-effects from using it. I agree its not the best medium to use, but, the point is, it CAN be used when other options are not available to us.
If someone is using tap water, and there system is stable, then so be it, it works for them. We have no right to start saying you must do this, or must do that.
Again, with the issue of copper, the thread is regarding fish/inverts, and not humans, so, can we please keep within the realms of aquatic biology, and not human biology.
Thanks
Niko