The picture in your gallery looks like a Condylactis species. They are notorious for wandering. As far as feeding, I do not advocate feeding a photosynthetic anemone more than once-twice a week in a tank with the proper lighting.
My advice is to get rid of it and consider a Entacmaea
quadricolor or Bubble Tip anemone when your tank is mature enough to support the needs of this animal. They are more colorful than the condylactis and will host different species of Clownfish, unlike the Condylactis. Since the Bubble Tip anemone is a rock dwelling species, it is more apt to stay put once it finds a suitable location. You can even build a rock corral for it when introducing it to your tank.
Please don't kill it! If you do decide to remove it from your tank. Return it to the LFS. Remember, it didn't ask to be put in your tank and has given its life to your whim. You have a responsibility to preserve the animals fate. All the best!
