First thing i would do. Is locate a park or somewhere that there is a stream. Then, take your significant other/best friend/family on a lovely day at the park. Then you can observe an environment similar to what you wish to recreate. There you can find your stone, with a lovely weathered look.
Depending on how much work you want to put into this, you could do a false background/corner. It will take a bit more time, but it's amazing what you can do. Check out the DIY section. It'll really get your wheels spinning.
hehe i spend most of my free time in parks anyway, but i have what i want in my head i was hoping for more options in the rock i can use, department. i did see a place yesterday that has some slab rock that didn't look like it was limestone based, i am gonna call them today.
i had been kinda anti false background because i always felt like it took away from space that i could have plants, but now that i think about it, it would make a great way to help hide my hoses and keep my tank clean looking. thank you!