If you sprayed heavily and the moisture did not dry up and your ambient was on the cool end then I could see a RI popping up. I spray every other day to 90% and that quickly goes down to 60% after a few hours from the heat lamp and then the next day its back under 40% and needing another misting. Is your T8 just heated by the flexwatt? Maybe the enclosure retains the moisture longer. What kind of substrate do you use?