My only thought is that I've used outdoor carpet/fake turf like this before and it tends to unravel a bit and for pieces of it to come off. Probably not an issue, but it would be something to keep an eye on.
If you have a wood floor my recommendation would be to put this on like 1/2 or 1/3 of the tank and leave the other part bare. You could glue it down to a thin piece of wood, like 1/4 inch, and have it as a removable solid piece, which would make it less likely bugs would get under it, etc.
I'd probably use contact cement or Shoe Goo to glue it down, and if you did either of those you'd want to let it fully cure for several days before putting it into the tank. Maybe there are other better carpet glues, I'm not sure. If you glue it down (to a separate piece of wood, not your tank floor) it would also make it less likely to unravel.