Can spinal stenos which is the cause of my sciatic pain. Get better with stretches, pilates, and water aerobics?

Spinal stenosis. Unfortunately, spinal stenosis as a condition will not improve with those efforts. Exercise may help you feel better in the long run as far as your mobility and pain level, but won't stop the progression of the actual condition.
LumbarSpinalStenosis. Most common cause of lss is degenerative arthritis, considered to be irreversible. In the absence of progressive neurologic deficit, trial of conservative nonsurgical treatment is recommended, but results are variable. Stretching, strengthening, and aerobic fitness are recommended with goal of increasing muscular stabilization and correction of posture. Surgery may be best option in disabling case.
Symptomatic. The symptoms of spinal stenosis, which include “sciatica” can potentially improve with aquatic exercises. The condition itself, which refers to a narrowing in the spinal canal, will not change. Good question.
Perhaps a bit. Spinal stenosis is an anatomical structural problem which will not be substantially changed by most non-surgical approaches. That said, really little problem with your exercise directions, as that may provide some relief from the symptomatologies. The longer you can manage issues conservatively, the better, but if you develop immobilization or bladder problems, surgery is necessary.