My anemone sucked on the pump but i quickly switch off the pump

If the anemones foot was injured,it wouldn't be opened up.
Leave the pump off. Maybe even lower the pump to the bottom of the tank and the anemone move itself.
+1 Yote!!! My RBT Anemone got shreded a koralia. I removed the torn tenticles from the tank & placed the powerhead/nem @ the bottom in hopes that the nem would move to a more lit location & it worked!
Also agree with Yote! My anemone was completely sucked into a powerhead and I assumed it was gone. I left it in to see what would happen and it made a complete recovery and lived for a quite a long time (I guess it made him tougher..LOL..)