It's been a month since you posted, but it's not that warm out yet, so here's my 2c.
Where are you venting the air? Can you intake fresh air from outside? If you're pulling air from inside the tent to the cool tube it's not going to cool that well, since you're starting with heated air to begin with. The most effective systems I've seen in operation don't rely on the light cooling for ventilation. If you can run it something like this:
Outside air > intake filter > ducting > cool tube> fan > ducting > Outside
You'll be a lot better off from a cooling perspective, you won't have to worry about odor being vented outside, though if you're not sure about the seals in your light you might want to put the fan before the light instead of after so the negative pressure isn't pulling odor in and venting it to the outside. Then just use your carbon filter on a fairly low speed to exhaust into the house, just to recirculate the air in the grow, though if you're using co2 you'd want to restrict the amount of re-circulation you're doing..