While there seems to be vastly different opinions and experience here, I've settled in on the assumption the humidity should be 40-60%.

To get there I added a small cool air humidifier to the cabinet and now have the temp at a comfortable 78 deg and the relative humidity around 48%. And I thought the kids were loving the MH lighting.. they're really perking up now. Pics once the Image Gallery returns..

Cheers, Farmer Rich :smokin:
Farmer Rich Reviewed by Farmer Rich on . Grow box humidity????? Hey folks, I've built a box with a 600 w air cooled hps and a substantial ventilation system. I can keep the box in the upper 70's but the humidity is running about 20% due to the amount of airflow. About 160 cfm in and 100 cfm out. This is my first grow and the plants are about 3 weeks and seeming to love the light. Won't the humidity climb as the plants grow? and do I have any worries with the current levels?? Thanks! :cool: Farmer Rich Rating: 5