65 gallon tank help

So, i temporarily have a 10g tank with 2 hermits. I know! Way too small. But its the tank I got from when I adopted 1 of my babies a few weeks ago. At the end of the month I plan on getting a much larger tank for my crabs (36x18x24), but i dont know how to exactly decorate it. I see some people have like, a side with just water? Like its blocked off from the substrate or something. I wanna add bubblers to this tank when I get it, but I dont know where to start right now. If anyone has any tips on materials to use or tank decor ideas before i do get the tank it'd be much appreciated!