I don't know if I said my words smoothly. Let's look at the air flow (how I recommend it) from intake to exhaust:

Lower area of tent intake hole with no fan, just passive intake. If you have your fan/filter that is just all the better. Then the air passes up to the carbon filter at the top. The fan sucks air directly from the filter, no pipes. From the fan via flex pipe to your cool tube and air flows across the bulb. Another tube to exhaust (not called "out take") hot air out of the tent. This will create a negative pressure in the tent which makes a passive intake possible.

Sounds like all you need is the tube or sealed vented hood.
Doc Oc