"Small" macros?

[Tired]

I know all macros will grow into big clumps if you let them, but some of them have a smaller structure. Like how short codium stays pretty small, and can easily be parted out into pico-sized colonies, where palm tree caulerpa gets large and in the way. Or how shaving brush algae is a single unit and not a spreading colony. C. prolifera has small leaves, but boy is that not for a pico. 

 

Does anyone have any macros to suggest that look good in small clusters, and doesn't tend to be too large? I have blue hypnea already, short codium, and a few bits of assorted red algaes. I like branching growth habits, and would like some green in here. The short codium is great, but that stuff's nearly black. I'm thinking maybe regular halimeda and the occasional bit of pruning. 

I tried some Cymopolia barbata, but it died off pretty quick. I think shipping riled it up, and it may not have been positioned to get as much flow as it wanted. Might try again and just anchor it to the filter outlet. It's so pretty, and branches nicely.

 

How big does H. opuntia/carpeting halimeda get?