Macro display tank.

[VietnamMinh]

Is it possible to grow feather caulerpa and other macros in a marine display tank and make it become a macroalgae dominated display tank?

 

[MomeWrath]

to my knowledge, macroalgae (especially caulerpa) are too unstable to be gardened like our freshwater aquatic plants. A macro-dominated tank would be subject to pH swings due to respiration during dark periods. If not maintained exactly right caulerpa can "go sexual"...put off a bunch of reproductive material and then the mother plant dies in a matter of a day and you have a mess on your hands.
I guess anything is possible but in this case I don't think the result would justify the work inovolved.