So who said that Soft and Hard coral cannot co-exist?

[this is me]

I was told that you can not keep soft coral and hard coral in the same tank or near each other. For this reason, I've ripped my tree coral a few years ago and sold it. After I have ripped out the green tree coral, my tricolor acro had encrusted where the tree was. But this green tree is a survivor! It poped out as a very very tiny blob and now it has grown to about 1". The foot seem to be under the encrusting acro. I thought it was pretty amazing. Just wanted to share. And no, I wont be ripping it off again.

 

[dz6t]

who told you that?

 

[marco67]

all I see is some sick mantel expansion

 

[ScottM]

its not that they can't co-exisit, but it is asking for a toxic environment.
Soft corals do not have physical defenses such as stinging sweepers, but rather use toxins to stake out thier territory. most people run carbon to combat this, but if your going to keep them together you'll find that the SPS will have less color intensity, and a slower growth rate. most people are pefectly ok with the trade off to have a mixed reef.

 

[Greg Hiller]

Plenty of people keep plenty of soft and hard corals together (myself included). There is no doubt that the soft corals put out some toxins, but as long as you leave some space between specimens, and use a little carbon you should be okay. Also, not letting the softies grow to ridiculous size is a reasonable precaution. Some soft corals will of course put out more toxins than others. I cannot give you a really good answer as to which are the most problematic.