Zoas need spreading.

IME corals burn each other/hurt each other, except for a few. Since you said they were colonies, what I would do is take some of each colony, and try this whole competition thing out. That way you may still have some left if things don't work out. Be sure to let us know how things work out!! I am interested!

 

Thank you everybody! I'm going to try placing them right next to each other and I will definitely post up results in a month and see if there is any change. I am still going to try and post a pic up, file is too big I'm assuming, so have to play with it. But thanks for the responses!

 

Zoas rarely will sting or hurt other zoas. One may outgrow the other, but the chances of them damaging one another via sweepers, or sliming is pretty low.