Planted Tank Guru
Join Date: Aug 2007
Location: Hendersonville, TN
I'm a little late chiming in, but how about just letting the two big bushes you have in the back span all the way across the back of the tank. Then, a red accent like L. Glandulosa would be very nice, probably about 1/3 the way on the left side.
Also, I'd spend some time hiding the equipment and lines inside the tank. I'd try to paint the filter tubes, or whatever is on the left side black, and move the heater (I'm guessing that's what the cable in the middle is going to) to a DIY enclosure outside the tank.