I went from "baby-sitting" a small 3" GBTA, to owning a monster 18" GBTA... all in about a 6 month time frame.
When I was asked to "baby-sit" this anenome, it was pale, and very shrivled up looking. The person that was moving his tank had NEVER given it any food, believing in "Survival of the fittest"??? One thing leading to another, a salt-water system never did get up and running again for my friend, so now his bubbletip lives with me.
I started out feeding it about 1/4 of a piece of raw shrimp, twice a week. I judged the size of the food, by the length of its mouth. True, I know its mouth can streatch, but I didn't want something that looked like it was just hanging on, to have to work too much to get its dinner. As it grew, so has the size of the food.
Currently, I feed it about twice a week... with either a full raw shrimp, raw bay scallop, silverside... or when I want to give it an extra treat, I do raw Squid. Since it is now this MONSTER in my tank, I think it has enjoyed the feeding. I try and varry what it gets for dinner, thinking that I sure don't want to eat the same food every night, why would any of the animals I care for?
I will have to also admit that my current tank setup is probably a healthier environment than what it came from as well. I have 1000Watts of MH, along with VHO actinics... excellent circulation due to a close-loop, and heavy skimming.
All of those things, along with the feeding, I attribute to the health of this Anenome.
The fact that your has "Found its home", and isn't roaming all over your tank is a very VERY good sign! They tend to continue moving until they find a spot that makes them happy. Several things fit into them finding that spot... like the texture under its foot, water flow, lighting, food, water quality, who is pestering it... and yours sounds like its a very happy camper!