Keep re-boiling the water, it must allways be super hot just the apties love it .
Pull the rock out of water so that the aptie is exposed stick the needle into its mouth and slowly 15-20 sec fill it with its fav drink, the anenome should start to swell and go white.
After practice if you rotate the needle all around the base of aptie you may be able to gently flick the anem off the rock as to not pollute the tank
HTH ben