Elite,
So you are just using tap water on your tank? I've done a few water changes with just tap water with no ill effects, I just use PRIME and an air stone for 24hrs before it goes into the tank. I was thinking about going 100% over to tap to see what happens. As long as you do consistent water changes I don't see why any negative dissolved solids (copper, silicates, phosphates) would accumulate, shouldn't they just be exported in the change? Seems like soon as you add one cube of mysis or flake food these numbers will go past anything you'd find in tap water. Have you ever looked at the ingredents on the back of Spectrum flake food? It list sulfate, copper sulfate, and ferrous sulfate (iron)....aren't these the reasons we don't use tap water in reef tanks?
Cheers,
Josh