Kind of amazed how many havent touched on the aquarium itself to be honest.
I dont think anyone is intentionally knocking it, but the set up isnt too great, especially for an Anemone.
They are one of the species of invertebrates that require very stable conditions, together with fairly strong flow and lighting.
Your tank doesnt look to have any of that ? Its obviously not too stable, with the cyano etc going on - The amount of air bubbles being pushed in must play havoc with the salinity too surely?
Your lighting really isnt sufficient for any type of Anemone to "thrive" and i doubt one wavemaker (if there is one) will provide enough flow either, being that its obviously not one of the more popular brands if there is one in the tank.
Kind of amazed at the recommendations to glue or tie down an Anemone that by nature will move itself too.
I really dont mean offence by the above - But my advice is to return it and concentrate on getting the tank tip top and stable before attempted a creature that relies on stability.
Is it really 8 years old? Where or what happened to the inhabitants in those 8 years?