I have something in my zoas. At first I thought it was aiptasia and hit it with lemon juice, but now I think its something else. Maybe some kind of hydroid or feather duster? Some times its there, some times I don't see it, but it never changes location. Unfortunately this is the best pi2c I could get, as its tiny. Note I've dipped this colony twice since I got it 3-4 months ago, and removed a small white worm two weeks ago.