My new 3x2x15” pvc enclosure has been up and running for a while. I have a 40 watt VE RHP, and temps are running perfect, but I am having trouble getting it to hold humidity. I have eco earth mixed with spragnum moss for substrate. I am spraying heavily once a day to keep humidity up. It still wants to drop. Substrate is not very deep. Would adding more substrate help with humidity, or is there anything else I should try?