When using mangroves for natural filtration, it’s best to suspend the plant above the substrate and keep the leaves out of the water. The roots will spread out from the bottom of the propagule, traveling downward toward the substrate. This is where the plant will take up the majority of nutrients. The leaves of the mangrove are where the salt is taken to and excreted. Additionally, the leaves will fall off from time to time, so be sure to collect them so they don’t decay in the aquarium. The most commonly used mangrove for aquarium filtration is the red mangrove (Rhizophora mangle), though the black mangrove is also used to some extent.