It is surprising to hear aquarists debate the efficacy of mangroves in the marine aquarium as vehicles for nutrient export when you can weigh their functional abilities clearly against their growth, which is dreadfully slow. In fact, their naturally sluggish growth is recognized by numerous governments on native coastlines where legislation controls or forbids pruning. At large, even occasional storm damage can be devastating. En masse, </em>in wild habitats, they are outstanding vehicles for nutrient export- fixing nutrients in their enormous and collective biomass. In the aquarium however, you do not have a forest of 20 or 30 feet tall mangroves... you don't even have one that big! The scrappy little seedlings that you do have, instead, demonstrate leaf growth concurrent with leaf drop at times. The proof is in the pudding, as they say: they are weak nutrient export mechanisms in the aquarium because they do not produce stable or harvestable mass quickly. If you are looking for a vegetable filter, there is a long list of algae (and even plants like some sea grasses) that can provide greater harvestable mass for nutrient export.
