Lowering humidity means removing moisture faster than the tent is creating or trapping it.
Searchers looking up how to lower humidity in a small grow tent usually want a fast fix, but the real answer is structural. Humidity drops when the tent can exchange air cleanly, when the canopy is not trapping moisture, and when the room feeding the tent is stable enough to help instead of sabotage the enclosure. In a small tent, even a minor weakness can push the air into a heavy pattern.
That is why the best first step is not guessing at the plant. Start with the room, then the exhaust path, then the canopy, then the water story. If the air outside the tent already feels wet, the tent is borrowing a bad climate. If the canopy is packed too tightly, the leaves are holding moisture inside the structure.
This page is the quick-answer version for the tent phrasing. If the enclosure keeps feeling heavy, pair it with humidity problems in a grow cabinet for the deeper enclosure diagnosis and use the daily cannabis grow checklist if the room stopped being easy to read.