I would think that it would have to be with a different tank. I remember that they were a little tricky to come by when we did this before, and it looks like these ones have been discontinued since. I just searched real quick and found it on amazon, but they only had one left and it was $50.
I would love to do it again, but am going to be way too busy the next few months to keep up with it.
I still have mine, free if anyone want to get back in. I'm done with this contest a while back, just like driving in a tunnel but never reach the light.