So here is my review of the Universal Rocks "Rocky 3D" background that I promised.
First, this is the background on my floor, just as it came. It's lying on a sheet of cardboard, which was in turn wrapped in cellophane. That's the company's packaging. Then, it was lightly rolled into another larger box and sent to me. (The product itself is quite flexible.) That box apparently came open during shipping, but there was no damage to the product, and nothing was missing. That was the fault of the store I bought it from.
As you can see, it's VERY thin, only about 1/4" inch. It's made from an extremely hard but flexible molded rubber, with actual rock particles attached to the surface and painted to look more real.
Here's another picture of the edge. I put my finger in the photo so you could compare the thickness to it.
Here it is with my new Beamswork Reef Bright light with the lights off in the room. I haven't installed it yet; I just set it in there loosely to give an idea of what it will look like complete.
A little closer with the lights in the room on.
Here's a close-up at a bit of an angle, so you can get a better idea of the texture. It's quite textured actually, for being so flat. The straight-on photos don't really do it justice.
And here's a picture from the side of the tank. Again, it's resting in there loosely, so it's not flush, but you get the idea. Again, you can see both the texture and how truly thin it is.
I spent just over $77 with tax for this background, and I've only found available to purchase from two online retailers in the US. My tank is a 55 gallon, by the way. They no longer manufacture the background with magnetic clips. The "clips" they had were just four uneven pieces of small PVC pipe with a slit, to hold the top of the background flush with the tank. In my opinion, the clips are about worthless. That said, I'm sure magnetic clips could be made, although I have decided to silicone mine to the back. It should be very easy, and there's a how-to video online. If necessary, it IS possible to cut the material, but it is VERY tough apparently. My guess is that a box cutter will work with some effort. As far as placing equipment, I would think that the heater suction cup could attach on the side in the corner as close to the back of the tank as possible. I'm still not sure about the intakes for the filter, though, and I haven't bought my canister filter yet so that I can experiment with the placement. That said, since I've seen pictures of others with the background installed and they had no issues, it must not be a huge problem.