Heya Whistly, I also have a simalar set up to Ebony but i have pebbles as substrate in the bottom of mine. I placed bricks where I wanted the plants and waterfall to be and once they were on top i built up the areas in front of the bricks with interesting river stones (bricks and stones were cleaned with water and then baked in oven first for sterilisation!) then i hid the bottom of the tank and bits showing through by chucking in a whole bunch of aquarium stones. My Golden bell is about the same size as yours and I have 3-4 inches of water in my enclosure. All my plants are potted eventually I'll silicone some sort of fake moss or maybe quickcrete or something on the pots so that they look more natural, I find it easier to fertilise them with that stinky fish poo stuff if I can just pull the plants out and do it outside.