^^^^^ that was my next question, about the lid. And remember that eco-earth (coco coir) will retain moisture, which in turn evaporates to create humidity. So make sure that the substrate has some moisture, but not sopping wet. The humidifier to make a fogger works awesome. Sharper image makes a cool one that is easily modified it costs about $60 or so. Otherwise, a controller in conjunction with a misting system or fogger will maintain a steady humidity level. My humidity levels spike when i mist, but stabilize after an hour or so.