I recently ordered a 4" X 4" radiator from Cool-Computer and found some corrosion on the fittings and inside the tube connections. I had not installed the radiator yet, and am leary of installing it with all of this white, powdery residue from corrosion. I am also finding out that aluminum and copper don't work well together, even with Water Wetter. Should I return this radiator? Is this corrosion something to worry about? Thanks for your help.