Star polyps and etc

[I666NoB666I]

Can these be moved somewhere else in the tank? If so, how? Also, I want to add a fish that is going to swim around the rocks a lot, any suggestions? I have 2 clowns, the fish that swims along the bottom and eats stuff down there, and another fish that just clings on the sides of stuff.

Also, on saturday I will be taking everything apart and cleaning them. Attached is a pic of the filter, should I leave that brown stuff on it or clean it off?

Thanks guys!

 

[salt_for_brains]

I am looking at the pics on my phone but that big one looks like aiptasia. Look up aiptasia anemone just to make sure.

 

[little_fish]

I cant really see the images, but you have plenty of fish for a 20 gal tank. In fact, I would say you have one fish too many.