Any tips on how to accomplish this aquascape

Im going for almost a garden kind of theme for my saltwater tank. It's not something you see often. I was looking up different macro algaes and I saw this video on YouTube https://m.youtube.com/watch?v=AJRsxcz6Zv0. I was wondering if anyone had an idea how to accomplish that? I wasn't sure if wood like that was safe for a saltwater tank, how do you make it safe for it. And how would I attach the dragons breathe to it. Also tips on the care of dragons breathe would be great. Thank you