adam does have a very good point. Where you just planning on using flexwatt or do you also have lamps that you are going to use? I have found that a problem with big enclosures (no matter what type of snake they are used for) is that the air temperture in the enclosure can change dramatically if the room temperature varies(i.e. one minute it seems like everything is great, then the a/c kicks on and temps are 5-10 degrees lower.) Be sure to monitor the temperatures all over the enclosure for at least a week at various times during the day to be sure that your temperatures are good all the time. If the temps are right, be sure to provide many,many,many hides in that large of an enclosure and even an extra water bowl in that enclosure to reduce stress.