So normally you think that the dishwasher should really take care of itself. I mean, it CLEANS!
But sadly, the dang thing needs cleaning out once in a while. So when I discovered that it wasn't fully draining (again) I went to take apart the main drain assembly under the sink. The last time it was clogging, I discovered that these things needed cleaning every 20 years or so. This is easy to do, by just unscrewing the thread, and sliding down the plastic off the sinks. If you put it in yourself and glued everything, well, you're in trouble.
So I took it apart and cleaned it. There was a table knife in the drain! So I really thought this was the problem, until I tested the dishwasher with the hose draining into a bucket, and the water only trickled out. Poops! I put in lots of chemicals.... Poops Again!
Then I found out you actually have to take apart the whole lower gungy thing! The internet was not clear on how to do this, but I found out that, for a newer GE model, you crawl in with a very powerful LED flashlight, and you see these tricky little plastic tabs under the rotating arm. This is the key to the whole thing! You barely nudge one with a flat screwdriver, and the arm just twists out counterclockwise.
Man, was that all really gross! Everything comes out easy after that, and you get access to the little sump hole. But I scooped everything out, and the drain still didn't work (I found that by turning off the water, and hitting Reset many times, all the water could be removed). Then, I went to the hot tub chemicals, and really put in something that sizzled! It worked!