Long tentacle anemone help!

[Longtenanemone]

I’ve previously had different anemone but this is my first with a long tentacle anemone. I have many years with experience so I know that the light and water is perfect for them but not sure what is wrong with my anemone, never seen this happen please help. Please only reply back with information on what’s going on

 

[Patrick Seastar]

It most likely past away. It seems like there's a bacterial bloom. If that anemone didn't pass away from anoxia, I'm gonna say it was because the amount of nitrogenous waste in the water coming from all the detritus.