Yeah mangroves can grow just about anywhere with A LOT of water. You mainly see them along tropical coast lines though. You can find some along the coast of Florida, S. Carolina and a few other U.S. States. However, I do believe it is illegal to cut down, remove, or even be caught growing these plants in some states due to their endangered status. Check with your local laws to be sure about this though. Only issue with growing mangroves in the home aquarium is that they are trees and well as most trees do they get to be large. Also if you’re growing them in saltwater the tree secretes the salt out its leaves so you have to clean them periodically.