Where to place carbon filter in a grow tent?

For a 2' x 2' x 5' tent, what would be the best place to put the carbon filter? I would think that on the floor right next to the plants would be the best place for odor control, but then I think to myself that hot air rises. However, I have measured the temperatures on the bottom and the top of the tent and the top was cooler by 2 degrees, which I guess is because the air cools as it moves up and the bottom is where all the light gets concentrated.

Thoughts?

i tied mine to the roof of the tent same with the fan

Up at the top.

They also remove excess heat, in a tent.

I used some zip ties to attach mine to the roof of the tent. I agree with the whole put it up high and get rid of the hottest air. You probably have passive intake on the floor of the tent - wouldn't want to be removing the coolest air by having your filter sucking it out as soon as it enters.

The temperature readings were probably lower at the top of your tent just because the top isn't subjected to the direct radiating heat from your light(s). You still have to consider that the coolest air in the tent is/should be entering the tent near the base of the plants and you don't want to remove that air as soon as it enters.