This could work well with mangrove plants by just hanging the planters lower in the tank so that the stems will have some space to lean forward. Most kinds of riparium plants do best with their crowns about even with the water's surface, but the mangrove trees and associated plants that I have tried have grown just fine with the planter several inches or more underwater. And mangroves would look good in a big tank like that.
Here's a quick picture of the mangrove planting in my 65G.
Here's a quick list of plants...
- black mangrove
- white mangrove
- red mangrove
- Pandanus tectorius
- Cryptocoryne ciliata
- leather fern
These are pretty cool plants. They will all grow in either freshwater or lightly brackish water. The black mangrove and red mangrove will also grow in higher SG brackish to full-strength marine water.
Hanging the planter down in the water will encourage the formation on stilt roots on the red mangrove and the P. tectorius
. Here are the stilt roots on my tectorius
There are a lot of great fish you can keep to represent a mangrove environment, too.