What kind of macro algae for nutrient export

[Fischer's Angel]

I live in the tropics and am unable to import or find "Chaeto". I would like to use some kind of macro algae for nutrient export in a 55 gallon tank that I am planning.
I can use the macro either in the display tank itself, or in a DSB I will be placing in my 30 gal. sump.
The only macro I can find in my area somewhat easily is Caulerpa Racemosa. Will that work for me?
Should I use it in my display,or in the sump? If in the display would the two 48" T-5 (1 daylight,1 actinic) be enough to keep it thriving in a 20" deep tank?
How often do I need to prune the caulerpa to keep it from "crashing", and do I need to add any kind of supplements to the water, or would 25% monthly water change replace the needed trace elements?
Thanks for the replies!