so say if i were to start up a fowlr predator tank the fish would be fine? what would i do about algae and stuff if i dont have inverts?

I've had a tank for 9 years. For the first 3 years it was fish only and I treated with Coppersafe the recommended amount more than a few times. I have done many tank upgrades since than and still have every peice of rock from day one. My tank is now a reef tank with anemone, about a dozen mixed kind of shrimp, some clams, starfish, crabs, SPS, LPS zoo's etc. I don't think I'm wrong to say that the Coppersafe eventually goes away.

There are a lot of great maintenance fish that can help deal with algae :-)

Personally, I would do a massive waterchange and use Cuprisorb which may help remove copper from the tank and any leaching from the rock. You may have to run it for quite awhile before seeing very low or zero levels.