transpiration is the cause, not watering. but is sorta related... cause if oyu starve it of water it obviously cannot transpire as much.
it will have a huge impact. the water provides building blocks for growth.. the atoms and molecules used to build everything. can't build new cells if the components are not in good supply.
you need a dehumidifier / improved exhaust or gas exchange with a less humid space or you need to grow less plant mass in that space.
if it's 20% hgher in the tent, then you need it close to 30-35% outside the tent, i bet...
if your region isn't humid, pumping the exhaust outside that room will help too - preferably outside.
bottom line is if the plants are releasing enough moisture into the air and you cannot mitigate it, you have too many plants relative to that space and characteristics of gas exchange in that space.