could be with my experience i would say yes. i set 4 23 watt cfl on the floor right after i turned them off for about an hour and it burned some of the carpet. how long are they going to rest on the tent?
Cfl's get warmer than you think.
If I mist clones and hit the bulbs they steam a little.
Not enough to make a fire but better safe then sorry.
That 400W is sweet enough.