When using red mangrove propagules as part of your natural filtration, do not place the roots into the sand. You might naturally think that roots need to go into the sand, but if you do that, then you’ll lose a majority of the mangrove’s filtering abilities. Since the roots are where a majority of nutrient uptake occurs, it’s best to float or suspend the propagule so that it’s root tip is in the water column high above the sand. The roots will grow out of the propagule and move downward. The exposed roots will take in nutrients, gaining more exposure to a larger amount of water. They will eventually grow long enough to go into the sand, which will allow the plant to eventually hold up its own weight and allow it to grow into a small mangrove tree.