Enough flow?

I have a IM NUVO Fusion 40 Cube. I only have a few frags in it with 4 fish. I have a torch that is really doing well. I think it looks better then then it did at LFS because the frag tank it was in did not have that much flow. I also have some zoas that are doing well along with a small acro that started turning bright green.



Here is my question. I am only using 2 IM spin streams on the returns. I get ok water movement. Should I add a Vortech or Tunze?