Most often a simple FW
dip is all you need to kill Tur
bellarian worms or you can use hyposalinity treatment. They are very easy to eliminate from fish. The only caution is they, like other parasitic problems must not have a host to infect thereby continuing the life cycle. I am not 100% sure but leaving the tank fallow for 6 weeks should be enough.
I have not heard of roundworms affecting inverts before, where did you find that? Some will prey on pods
but they do not in fact "infest" them the same as corals or fish.