mine took about 20 minutes but they were already paired with a BTA at the LFS. they knew what to do as soon as they found the BTA and now attack you if you even think about coming close to there anemone. they have gone carpet surfing a few times while trying to bite my arm and hand. carpet surfing slows them down for a few days then its back to full on attack mode.
i have had my ritter anamone for about 7 years now he some times gets as big as two basketballs.. he has started off in my 45 corner tank to my 120 gallon to my newer 220 and evertime it goes right to the top middle of the glass of the tank