Anenome not Acclimating to New Lights

[kien]

What kind of anemone is it? Just curious. It can take then a while to acclimate and as already mentioned, often times they will move on their own to fun a suitable home (in terms of both flow and light).

Do you have any shaded areas in your tank? If you do you could try putting them there. How deep is your tank? Raising the lights with halides might not make a big enough difference as halides tend to be quite penetrating right to the sand bed!

The screen over the tank (just over the area where the nem is) is a great idea. You can even layer egg crate if you want.