How aggressive is aggressive?

[jamesrm]

I am starting a new reef tank, 125 g, getting a local company to assist me with the setup. I am looking at liveaquaria to get an idea of the corals I would eventually like to have, and I am curious to how "aggressive" aggressive coral is. Will it seek out and destroy its neighbors/fish? How can I figure out how large different specimens will eventually be?

Links to two examples that I like:
Drs. Foster and Smith Diver's Den® - Euphyllia paranchora
Drs. Foster and Smith Diver's Den® - Euphyllia glabrescens

Thanks!

 

[pat8you]

Aggressive coral usually means that it has longer sweeper tentacles then most coral. I would give an aggressive coral 5-6 inches of room between it and any other coral. there are a few coral that will need even more room then that. Coral will not hurt fish with the exception of a very very few. Only two i can think of are the elephant ear mushroom (never seen one in a LFS) and a carpet anemone (which you should not get until you have quite a bit of experience). Most coral if they are healthy will continue to grow indefinitely. You can trim then back in most cases if they get to large.

 

[xsmoker_3]

My hammer coral needs lots of room as soon as i get anything within 6 inchs they start getting stung. but it is a fun coral and its realy neet to see them start to split into three branches....mine started spliting a month ago