Thanks for all the replies!
I'm not exactly sure how they spread. I know there is encrusting and branching, both of which I have. You can see new polyps popping up on the colony's all of the time, but I too see little miniature polyps all over my tank.
Anyway, here are some new ones I got for X-mas. I was looking for some reds, but they are pretty rare and hard to find. So I found some really dark orange ones. They are very pretty, not quite red, but obviously different from the normal orange. I got them yesterday. Most of them came out and ate last night, and overall they seem healthy. The pics don't do them justice.
![](https://forums.saltwaterfish.com/image/noimage/true/width/525/height/525/flags/LL)