It is a balancing act for sure. In tents the temp may be a bit higher. The HPS lights in this set up give off enough heat for my registers to be closed. Yes, this temp stays stable I close the window at lights off.
After I water at lights on the humidity climbs levels off then drops.
This is just what this stoner does
There are a lot of variables to align to make things work. At 50% RH I am guaranteed mold