My tanks have pretty good seal with glass tops so the amount of evaporation from the tanks is minimal , my dehumidifier has a humidistat set at 50%.I don't mean to get off topic but, Isn't a dehumidifier in a fish room kind of a waste? Their job is to pull moisture from the air so with a bunch of tanks, it's not going to dry air and going to suck up a ton of electricity. Excuse my ignorance but am I missing something?
With summers here, outside humidity in July and August is sometimes > 60% .. so any relief in the fish room is welcome.
To the OP the only smells I get in the fish room are from the food itself. I feed a lot of massivore , NLS thera + and garlic soaked soft foods..