Kryptonite candy kane, branching vs ball mass

[TangingOut]

Looks like my 3 headed frag is going to be the ball type colony. Why do some ball while other colonies branch? I was/am hoping mine branch.

 

[jayball]

If you look here:
http://coral.aims.gov.au/info/factsheets.jsp

It looks like mature colonies take on a mostly ball shaped appearance. You could probably create a branching colony with generous pruning, like a bonsai tree.

 

[twon8]

Maybe very low flow?