I have just remodeled our kitchen. Installen granite counter tops and an undermount 10 inch deep sink. I also purchased all new applicances. All of my under the sink plumbing worked fine before. When hooking up the new dishwasher and just draining a sink full of water. The water backs up and doesn't drain. The hose from the dishwasher to disposal is new, its not clogged. I disconnected the plumbing and the water drained into a bucket, so I now its not the hose or garbage disposal. I snaked the water lines and found no clogs. I did notice the disposal sits lower than it used to. I got the installation instructions out for the disposal. It says that there must be a 5 inch drop from the center line of disposal outlet to the center line of the pipe going out the wall. I only have a 2.5 inch drop now. Could this be the problem? If so is there an easy solution? Or am I going to have to have a plumber move the main drain pipe down 2.5 inches? Please advise.