I recommend a terrarium with a sliding and locking lid, like the kind zilla makes (Like the ones on their website here, but also easily found at any pet store). I use two of the 20 gallon sliding lid tanks and it's nice, because I don't have to worry about those snakes ever escaping. However, if buying a whole new tank isn't appealing to you, I also use tank clips for my tank without that style lid (again, you can see them here, but they have them at any pet store). Personally, I wouldn't use weights just because I'm not sure how much weight the screen lids can handle if bigger weights like those shift around, and the last thing I want is a heavy weight falling into one of my tanks.