That's what stumps me too, I have it in live sphagnum aerated with perlite, kept wet but not sitting in water.
I tried keeping it drier earlier, but it grew really slowly. Oddly enough it took off like a rocket for the two weeks I went back home in San Diego, and then stopped again once I got back here in Nashville.
In any case, I moved a small chunk into a tall jar with an inch of water at the bottom, but not reaching up to the live sphag the utric is in. Hopefully it'll do better in there.