i have taken a new approach to caving. I created a latice and gone into the editor and started from scratch and drawn it as if was pouring liquid from a bottle. (peter sharpe's tutorial for reference) I lengthened it to be one side of the cave. I made another one the same length and grouped the 2 and now have a long tunnel very cave like. I have also added stalagmites in the same manner as you described, and rocks and sand for the floor.