[Silverfish]

Hi Marco, an anemone would probably not do very well in your system, as you said. I have heard people using some soft corals as a surrogate host for your clown, namely Sarcophyton sp. otherwise known as toadstool coral, leather coral etc. They are pretty hardy and it may work. I have also heard of clowns living in some LPS, but I don't know if you are ready for that yet.
HTH