Originally Posted by lbannie
kill Soft corals if too close?
Like many of the answers already, the answer is a big, resounding... maybe. It really depends on the corals, and even then, it's not consistent.
For example... I have a TON of little blue snowflake polyps in my tank (sansibia/anthelia) which are soft corals. I have a Lobophyllia (open brain) coral right next to a patch. The Sansibia is touching the Lobo all over the place, but *most* of the time, the Lobo doesn't care. But occasionally, the Lobo sends out mesentary filaments (serious warfare... not just the normal tentacles) and just totally wipes out a patch of the Sansibia that is near it. Then everyone goes back to their happy selves and the Sansibia lives peacefully next to the Lobo. Go figure.
I've also got a Platygyra (maze brain) that is next to some plain purple Mushrooms. The Platygyra will send out some impressive sweepers at times, which you'd think would be pretty potent. But if a Mushroom even touches the edge of the Platygyra colony, the Platygyra will start to recede in that spot within a day. No warefare, no sweepers, just instant death. No problem though... I just remove the mushroom and within a week the Platygyra has recovered and continues it's slow expansion to take over its rock!
So there are not many "for sures" when it comes to what will win. But I agree with others... Torch corals will normally ALWAYS win, so don't make the mistake I made and locate the torch in the middle of your tank. It just makes it easier to reach everything and cause problems.