I have a 1.2m x 1.2m tent with a 600w MH for veg period. I have my CF on a 4" rvk fan for extraction and a 5" rvk fan for the fresh air intake. My temp gets up to 30c sometimes. Am I better off having a cool tube on a seperate circuit than the CF to bring temp down? I have used the cool tube last grow but the yield wasn't too good compared to when I use just a reflector. What I'm asking is which is more harmful for yield? 30c temp or bad light dispersion through a cool tube.