[reefnoob1991]

That is a condylactis anemone...almost positive of it. Second, adding stuff wayyyy too fast...mandarins should at the very least be put in a tank of 75 gallons after a time of no less than a year,even at that time they may not even have enough food. They're like sand sifting starfish, they spend their entire day grazing for food and once it runs out they starve. Take it slow, "Rome wasn't built in a day, neither is a reef"