Carbon Filter + Cool Tube questions!

I see that some of you guys suggest hooking up your cool tube with your carbon filter in order to cool the light and eliminate odor at the same time.

Do you run your inline only while the lights are on or 24/7? Will running your inline 24/7 waste up your carbon quicker?

About to get some HPS/MH lighting going on (only 250w, nothing TOO fancy) but I was worried about heating.. Also getting a carbon filter + fan combo so if I could hook it all up together as sort of one thing and kill two birds with one stone that would be great.

your plants stink 24/7? mine do.....peace

They don't smell as bad when the lights are off , but Yh u would be better running it 24/7.

That's all I need to know, thanks for the help ya'll +rep

Yh u should run it 24/7, the plants don't smell as much when the lights are off so it won't make a massive difference to the life of the carbon. The life time of the filter is judged with it being run 24/7 anyway. 2 birds with one stone is good