Since it's already in your tank and is looking healthy, I would not take it back but leave it there. Your tank has better conditions for the anemone than the LFS
. Moving it now that it's attached to rock won't help it and will likely damage it. You have a lot of LR
and moderate lighting. Feed the anemone. Don;t increase the bioload for a while. Keep checking ammonia and nitrate. With enough LR
your nitrate should stay at zero. You tank looks good, just let things be for a while.
By the way, your clown is awesome! Hope they both survive.