Endless Pool or other exercise Pool workouts?

I have a Rio Swimspa in my basement, like an Endless pool, but with giant jets and stronger current..  It was my wifes requirement when we built a new house, but now I use it more than anyone with my training.  But I don't have a clue as to any distance or time for a 100 when I am working out.  The only pool I have access to is about 30 min away and is only a 25M.  What methods for training have people used with exercise pools?