Hi guys, let me start by admitting my lack of plumbing knowledge or skills. I have a kitchen sink that is backed up. The water starts standing within a few seconds of running the faucet. I took apart everything under the sink and cleaned it out. I snaked the pipe that goes into the wall under the sink. The house was built in 2000. None of the other drains in the house are clogged although my bathroom sink needs drano every few months. Any ideas?? Could it have something to do with this water purifier that's hooked up. That thing started leaking a year ago so I just shut off the water lines running to it.? I'm super lost. I'd appreciate it if you can keep it really simple since I have no idea what's going on.