Don't you believe it Ira, they stick like glue! You have to prise them very carefully with a knife. Once you get the edge lifted it breaks the seal. You have to be very careful with the anemones, nothing too sharp, or they die. Try to find some which happen to be on a moveable rock and add them, with the rock, to the tank.
Chris, I did not do water changes as they say.
We froze the water inside 3 litre juice containers and floated them in the tank. As they thawed they were put back in the freezer and replaced with frozen ones. At the height of summer we were having to freeze 18 litres a day!