I've never heard of a ric melting. Are you sure it didn't come off the plug? I don't see how leaving a powerhead off would cause it to melt. Did you actually see it fall apart?
Let me see if I can describe it. There was maybe two blue nodes on the left side and the whole rest was an ugly gelatinous, light grey mass that was starting to flow off of the plug.
It was such a cool color too. Sorry Levi.