Our Mangroves are growing very nicely. We have plenty of them between 6"and 10" tall. We have both sprouted and unsprouted and are happy to explain the conditions in which they are growing (or were collected) for smoothness of relocation for you! Mangroves surely add a fantastic, unique look to your tank or refugium with their unique stem/trunk and thick green leaves. . You may possibly want to grow your plant in a removable pot (within your tank).  Or, you may choose to experiment with pruning the plant as it grows in an    effort to manage the roots.