Thanks for the comment.
For a long time i had it without any background, so you could see right through it to the other side of the room. But the problem with this is, i had to hide all the cables at the one side facing the wall, and that left me with bad flow through the filters. In other words, dead spots were all over the other half of the tank.
With a background on, i can have tubing and cables going in and out of the tank anywhere i want, without it being seen.
I have tried with several really powerfull stream pumps and powerheads to create the proper flow, but there would still be an undesirable dead spot near the bottom of the right hand side of the tank.