I assume you are speaking of Goniopora. They are misunderstood in terms of their needs, and therefore, are difficult to impossible to keep for more than 6-12 months.
I kept a Goniopora for 1 year before I knew about how difficult they were/are. During that time, it grew 6 new branches and then very gradually started to shrink and die. The shrinking happened after an urchin stabbed its flesh with its spikes. This probably resulted in a bacteriial infection. I removed the urchins, but have not bought another Goniopora because they are extremely difficult to keep in captivity. They are very pretty corals though.
I purchased one about 2 years ago from my LFS. It did well for about 3-4 months until my percula clowns started making it a host. This apparently bothered the flowerpots too much and they slowly began to die off and eventually did after a month or so.
After reading up more on them, I would probably not attempt to buy one again. My bubble tip anemone, on the other hand, is still going strong at 4yrs and counting.
Flowerpots are very easy to keep. They are actually hard to break. I had one in a 20 gallon with NO lights and dirty water, and I still kept it. No problem. The clowns laid eggs on it. I think the only way you could break one in the tank would be to drop a rock on it. Buy a flowerpot. They are nice and the fish like them.
Everything I have read says that they are not good to get. No one knows for sure what it takes to feed them so I would suggest that you pass it up. If people continue to buy them, then the diverscontinue to collect them. One day someone will figure it out and we will all be able to enjoy them at home. Glad you asked first. Most people buy the pretty coral then ask later...
What? A flowerpot is a coral? I was refering to the round red flowerpots that breeders use to get clowns to lay eggs on and most people use to put flowers in. Sorry, I will not try to be funny again.
I thought you would have caught on when I said the only way you could break them was to drop a rock on them, and that my clowns laid eggs on it. Here is an old picture of my unbreakable flowerpot that was in a 20 gallon with NO lights.
[ January 04, 2002: Message edited by: chris_h ]</p>
OK I'm a newbie, but I have noticed many online retailer refuse to sell Goniopora because they are so hard to keep. Leave the mysteries to the gurus and only buy the animals you think are definitely sustainable in your care. Otherwise you are wasting life. Life is not like time, at least when that life is not your own. OK I'm done pontificating.
I have a gonipora and it has been doing fairly good over the last 7-8 mos. (I know I have not hit the magic 1 year mark, but you never know.) I bought it when I was told it was easy to keep and would not buy it again. I find that it is both a waste of money and of the animals life when almost all will up and die. If you want to read about possible requirements goto http://www.reefs.org/library/article/r_toonen20.html Keep in mind that the article was written in 1999 and 3 years later we do not seem to understand much more that back then. They are hard to keep, require light, warm temperatures and very dirty water. (by out standards.) Who knows, someone may just find the "key" to keeping them, but until then I would stay clear.