So I have a rather long story about my kitchen sink. I moved into my house about a year ago. From the time I moved in I've wanted to move the kitchen sink to be in front of the window because to me that's where it makes the most sense. I'm on a slab concrete foundation so I knew the "right" way to do this was to have someone come out and jackhammer up the concrete and move it over to where I wanted it. After hearing the price to move it about 9 feet I decided there was no way I was going to do it that way. I decided I was going to DIY it and go through my studs. It is on an exterior wall, but before everyone grills me about it freezing, I will take the proper measures to make sure that doesn't happen before I put the drywall back. So I cut all the studs and get the pipes in and glue them up and run it. I had about a months worth of dishes piled up so it took me a good hour to do them all. 30-40 minutes in not a single leak and its draining like a champ. Well I look in the corner at one my sweep elbow joints and its got a drop of water on the paper towel I put under all the joints so I could see the leak. After about 10 more minutes another drop. I decided any drop was too many so I cut it out and put a new elbow on. This time something happened to were it wouldn't drain. I looked at the pipe coming off my p trap and it looked to somehow be on a incline. I don't know how it happened but I know water doesn't like to travel up hill so I cut that out and redo it. After my third attempt I turn the water on and it drains properly for about 10 seconds then starts to fill up. After the water is shut off it doesn't take long for it to catch up and drain it so it is draining it. I can't figure out why it's draining so slow everywhere I look it appears to have enough slope. I know the question will come up about venting. It has a vent next to the drain location. I thought about this being the issue but the first time I had it going before I got the tiny leak it seemed to drain just fine. Please if anyone has any tips or suggestions on why this might be happening I would greatly appreciate them.