I've had one that big and they are very very prone to leaking, (mine did after 2 years on a new house) , because once they start leaking around the edges (like they eventually all will) you are fuxored
it usually messes up the drywall because it turns to mush when wet and you end up replacing the whole ceiling
these are not as prone to leaks and are pretty cool and accomplish the same effect, sunlight, they also have a light fixture built in for night use
http://images.google.com/images?um=1...sun+tube+light