turn off as much of the circulation as you can for about 30 minutes. take a flat rock, and put it down in the sand so that if you covered it back up, it would be about 1/2" below the surface of the sand. put the sebae's foot on the rock and gently pile the sand up around it. after about 30 minutes, slowly start increasing the water circulation back up to normal. this has worked for me in the past. if that doesnt work, try the same thing, but also place some smooth pieces of lr around the outside of the foot and then carefully pile the sand around. i had one that would move about every three months and i would go thru this procedure and it would stay put for another three months.