Don't put copper in with rays as it is likely to kill the rays.
My rays love snails, they cannot get enough and keep the tank 100% snail free, the sump has loads so you can tell that the rays are eating them all in the tank.
My rays love snails, they cannot get enough and keep the tank 100% snail free, the sump has loads so you can tell that the rays are eating them all in the tank.