Thanks, I probably won't mod it, no. It's hanging on the back and it's pretty sturdy, though it's running on an angle. You can't see it, but there's a groove in the lip of the glass back there that's a perfect fit for the HOB. There was custom plumbing that came with the bowl(s), but in my opinion, it took away from the look. I'd rather have something on top than pipes running all around the bowl. I'm not too concerned about the water in the smaller spheres. If it gets bad, I might have to use a small canister + the pipes, but it should be fine if I'm careful. And there's nothing a water change can't fix!