Well, the print is a little small but I think you can get the idea.
But some how make an island in the tank between 1/2 and 3/4 of the way up the tank, for crabs or something to live on. The island would be a box with 2" sides to hold in the substrate. Bottom would have holes cut in it for plants. I was thinking of using the pots you buy plants in so I could plant the plant with a little gravel around it, stick the pot partway through a hole so the plants could get water
The island plants would hopefully drop roots down into the water so I wouldn't have to water them.
The fish part would like like a big circle track with a light current flowing with the arrows. The divider would be plexi-glass or something clear so you could see the back side.
Any imput would be apperciated. Good idea or bad idea? I am not going to attempt this for a long time. But I would like to someday. Has anyone seen or done something similar? I know there are terrariums but I've never seen one like what I was thinking about doing.