[Ross]

Magnus, I really think that with double glass between the lights and the fan, you'll not have to install cooling. If this were my tank, I'd consider installing small D.C. fan to blow room air between panes of glass, say 8cm DC fan (computer fan). I think your problem right now is the fan you have up there is capturing the heat from the T5 bulbs and blowing it down into the tank. Can you change location of fan(s)? Say mount the big fan on outside of tank in corner near top and have an outlet hole same size near bottom on opposite side? This would force room air through tank. Of course, humidity would drop so you'll need additional misting capabilities or some way to have fan blow across water reservoir. I think you've got a great start, just fine-tune it a bit.