I have heard Ackies do good in trios. Also I think the minimum enclosure size is around a 5x3x4. I saw a thread about someone building an enclosure for Ackies and they used what looked to be a giant cattle water tub. It was about 6 feet long or so and 4 feet deep. They filled it with dirt and then built a supporting frame around the whole thing with plywood and lumber. It seemed like a great idea.
Here is the thread. It also has a lot of information on raising Ackies
http://www.ssnakess.com/forums/varan...estions-3.html