Well, the pipes are like that to allow me to tweak the water flow. 12,000gph flow takes a little planning.
One of the gremlins to sort is the fact that right now my tree is moving in the current. Having said that, I like the outflows where they are, or at least external like they are. The initial plan was to have them coming out of the boxes through the background. For reasons that will become apparent when I post more pictures of the setup, that's not feasible. And I think having the outflows plumbed through the background would be an uglier wart...at least that was my decision. I guess I could paint the PVC. But to be honest, they don't bother me at all.
I guess the only way to conceal them would be to put them behind the background. Want to guess how many holes would have to be in the background to facilitate 12,000gph exchange between the two sides of the background?