do you just have the hydroton on the top layer? and if so, what is the benefit? does it help keep moisture in?
do you have any exhaust?
.... lol sorry for all the questions - just curiosity
I've found that giving specifics on this site go a long way.
your setup looks real clean so far dude, good luck on the grow!
if you need any help with ventilation/ cooling you can feel free to ask anytime.