None of mine have an odor that i would say is bad yes a certain odor you can idenify but i think its just the moisture of the tanks. But i would advise you not to spray anything to near the tank as any air born chemicals can easily enter a tank and its water. This would not be good for you or the fish. Try doing a good water change and take a good look aroung in the tank for decaying plants of fish. If nothing maybe try a gravel vac while doing the water change and keep this up for couple days.
Are you having any weird ammonia, nitrite readings?