I received my anemone from divers den 3 days ago and the first day it was open and his mouth close. Ever since then it's been deflated with his mouth open(occasionally it will tighten up) with brown stuff near it's mouth. But when the lights are off it's inflated with its mouth closed. The tank is 29 gallon that's been up for a year and a half with a nanobox duo for light and 0 nitrates. What should I do? Also it hasn't moved at all and it still looks like it has all its color.