Happy Holidays Everyone! So, My upstairs bathroom sink drains terribly slow, and now has standing water. I've taken apart the trap and it is very clean, and I also tried using a wet vac to clear any block, with no luck. Here is a picture of the plumbing (not sure if this will help): This may look familiar to some of you - that's because I recently replaced leaking galvanized nipples with brass you see here (thanks for the help!). I noticed that the drain for this sink is also galvanized pipe, and I have a feeling that the inside of this pipe will be just as clogged up with black stuff as the old nipples were. I have about 3' - 4' from the PVC/galvanized junction to the main stack (behind the wall). Can you guys recommend a tool to clear this line that I can pick up at one of the big box stores, that actually works?