its probably a good idea to turn off the flow to let it attach to the surface. Anemones will move around by themselves to find a home where its happy with the light and flow. did you just buy this one ? its unhappy and bleached.
It will most likely move to edge of a rock by the sand bed to wedge the foot. Don't worry it will color up. Just got done treating one that has more zoa anthology than yours but is still not sticky yet. If yours is nice and sticky it may be pretty healthy and color up fast. Nice grab