Sacroiliitis and Aqua Aerobics

I've posted on here before about sacroiliitis.  I find it catch-22 as I'd like to stay healthy, but yet when I work out to stay healthy, I always pay for it with my joint/back.  If i'm lucky, then I'll just be very sore the next day.  It I'm unlucky, I'll cause a flare up where I can barely move with shooting pain and it will weeks to recover (and I no longer fully recover, but hope for the shooting pain to go away).

So my question is....what kind of workout can I do?  I love the eliptical but that's waht always eventually gives me a flare up (even if i do it at most once per week).  I also have a stationary bike but also find my back gets very sore after sitting on it for 20 minutse.  There are aqua aerobic classes near me.  I hate the water (and I cant very well listen to my ipod at the same time) but am wondering if this would be good.  Or would this still put a strain on my joints or cause issus if I move the right way? 

Would love to hear from others in the same situation.

I've suffered with SI pain for years and actually have managed to get it under control with diet and exercise. It flares, but not as bad as it did before I got on my regimine. In terms of exercise, the best bet for cardio is the recumbent bike. It keeps you hips in place, and there's no impact. Make sure you work you're way up to higher resistance though -- it's easy to just sit there. Occasionally I cheat by taking a run (esp on a nice day)... I pay for it though...

Thank you.  Sounds like the aqua aerobics is worth trying.  Gotta get me a bathing suit first.  

mdman, I don't have a gym membership and only have an upright stationary bike.  Too bad it's the other one that may be better for me.