so I got a new tank not too long ago and I am having major problems with keeping the humidity up... it's a fifty gallon terrarium with a mesh top and I have tried everything I can think just short of spraying water in it every 20 min.

I built the DIY humidifier, I covered the top of the tank with tin foil and cardboard, I just soaked the repti bark I have in water for a good half an hour and the humidity still hasn't raised above 40%, oh and I have two water dishes one of which is directly below a ceramic heat emitter