Can be done. the trick to it is to pluck all but one leaf on the mangrove when it is at the size you want, and this will keep the plant form growing too tall and it will put most of its growth into the root system. Is it worth it, depends on what you are trying to do. will take some time to establish the system, water movement must be properly slowed to allow sediment drop out, ect. etc. so my opinion is it would not hurt to try it as long as it was not the only method of nutrient removal. if it is then a refuge with sand or mud and algae would produce better removal.
