you didnt mention what type of system you have, i notice its a tray full of hydroton but what is your method of watering? you do realize if your roots are in the hydroton alone not sitting in some sort of res they become dehydrated very quickly, i have my girls in 2gal pots in a ebb and flow with just hydroton but i have to water every half hour or they start to droop, hydroton is the best in aeration bar none, but you gotta keep them girls hydrated, also another tip is keep the ambient temptures around the hut low and you shouldnt have a heat issue inside, you have your exhaust down tight, just make sure its cool air your sucking in, other than that deftdrummer hit it right on the head, good luck

oh yeah how much hydroton did you waste?, that stuff can get pricy