Hi I just purchased a house and I’m pretty clueless with plumbing. I have a kitchen sink that backs up when I turned in the garbage disposal it fills with black water and Little Rock like black chunks. I tried Flow Easy drain opener, then it backed up again after using the disposal then my disposal leaked all over my house. Then I replaced the disposal and snaked the drain and it still backs up. Only other idea I have is possibly a clogged plumbing vent? Any ideas?