My PT tells me aqua therapy is great in terms of building strength, but it will not help with balance as the water does all that for you, so it does not challenge you to work on your balance.

If you want to work on your balance, do it on dry land - wobble boards in the middle of parallel bars so you have something to grab on to, standing on one foot, or if you can't do any of that (which I can't) sit on a swiss ball and slowly raise one foot at a time.

Have your PT work out a schedule for you if you want to work on your balance. Personally I did not find exercise helpful for improving my balance or posture, but it certainly has improved my muscle strenght which is really important. I have numb feet too, plus a variety of other balance issues.

hth
raglet