About a rock wall
 

If a tank has a rock wall in it does the filter go behind it or over it? kinda a stupid question it just seems like it would be too thick for it to hang over it.

Also, does anybody know a good place to get a rock wall thats nice but not bank breaking?

This is the cheapest you'll find and it looks it a bit, but once algae and aging sets in, it will look fine. Use long stem plants to hide the seams.

http://www.hagen.com/uk/aquatic/prod...01117910030101

Of course there are much better ones, but with much better prices, if you know what I mean as well:

http://www.gillsnfins.ca/

Oh wow that lake tanganyika one looks amazing