I used dissicant packs on another housing. But I pretty much gave them up as a bad deal. I dive pretty much in warm water. If you are in an air conditioned room, you can close up your housing in the room. The air in the housing will be drier and colder than the water. So you will not get any fogging on the inside of the housing. Of course, you will get immediate fogging of the housing the moment you leave the room and your cool housing hits the warm, moist tropical air. But once the housing warms up, that goes away.