I've read that they use up a lot of mag and the roots can get into the silicone in the tank causing leaks, still I always wanted to set up a tank with the root system as part or the aquascape. When I was a kid I went snorkeling in a lagoon/mangrove forest in Puerto Rico and it was awesome. I always though it would be cool to recreate that environment but I'd imagine the mangrove would have to be quite large to have the same effect. I wonder if you can continually prune the tree to keep it some what on the smaller side kind of like you would a bonsai.