"The first one I actually measured out and "designed" according to the golden rule, but it looked too structured, and didn't have anything going on in the background. Considering most of the fish in that tank are African, I kind of like the lack of vegetation. Maybe you could spit some ideas out about rearranging the 3rd picture?"
Doodled around a bit tonight, it's kind of hard to explain and easier to do but I hope it translates pretty well. Obviously it's color coded here, easiest way I could think of doing it.
Start with the easiest points here, some thing barely move in the tank.
light blue - stays where they are
light green - this branch moves from the front right corner to the back right corner
dark green - flips over and the single end rests in the right back corner behind the light green branch and leans across the back at an angle, resting within the light blue branches if needed
dark blue - moves forward almost to where the purple branch is now
purple - branch moves forward and more centered and leans against the base of the orange branch
yellow - moves from the right side to the left back side where it leans against the top corner at about the same angle it's at right now
red - this branch moves to an angle with the right front corner and goes diagonally towards the middle back as it slopes down.
orange - right side of the branch is lifted and rests across the red branch now so the bottom left end is in the front left of the tank and the right end points towards to right rear of the tank
black - round stones added for a change from plants. one is used as a end holder in the left front corner to help keep the orange branch where it needs to be, one used to brace the purple branch, and one used for balance (threes) keep in mind the approx size of stone I used here, there's a small, medium, and large, balanced in their location.
The tank now draws the eye across from the front left to the back right, across to the back left and back to the front again.
