Nice, like the mangroves and tile back wall.
I was actually thinking of using travertine as a base for a back wall on my reefs, just need to make sure it doesn't leach anything bad.
you should think about trimming that larger mangrove soon, if it doesnt branch out soon, it will get real tall real fast. That's what happened to mine... I waited way too long to trim.
I think that the mudskippers are fascinating and your system is really great. I like how natural it is instead of looking commercial. Great job! Hope you post more pics as the system changes and the mangroves grow.