I've had the mangroves for a number of years. Initially they grow kind of fast but then they slow down. I suppose lighting has something to do with their growth as well. I don't think the light I have them under is ideal for them as they would likely prefer more of a full spectrum light where as this is a 12,000k Maxpsect Razor that's over them. Also keep in mind that while mangroves are neat, they do little to nothing in terms of benefiting my system (nutrient reduction) due to their slow growth and the fact that I only have two of them. As such, they are more of a novelty for me.