Alright so I have a 20g l tank that is covered on top with wood and has vents near the top of the tank. I have a large water bowl in there and my hygrometer is reading 80% humidity. I don't know if this is true but I exchanged the hygrometer today because it said the same thing yesterday. Outside of the tank it reads about 40% humidity. It is not a digital hygrometer but I am not sure what's going on. If it is really 80% humidity is that bad. Thanks.