How to Get Rid of Black Sludge in Sink Drain

Are you wondering how to clean black sludge in sink drain? The slime you see collecting in your drain is a common occurrence, and with the right tools can be prevented or cleaned out.

What exactly is that sludge? What materials are perfect for this cleaning job? Hopefully this guide will help answer your questions.

How Black Slime Raise in Sink Drain?

Though it can look pretty disgusting, the black slime that’s hiding in your sink drain is easy to explain. Mostly it is a collection of grease, dirt, hair, and other residual grime that has built up over time.

Hair is usually the main culprit of clogs and sludge in bathroom sinks, and grease and oil is the main offender in kitchen sinks.

3 Methods to Get Rid of Black Sludge in Sink Drain:

Sometimes this problem builds up gradually over time, and prevention is no longer an option. Try these methods for cleaning out the sludge from your drain.

Method 1: Drain Cleaner

How it Works:

Drain cleaner is a heavy-duty chemical that is intended to dissolve any sink clog. These chemicals can often be abrasive on materials such as plastic or acrylic, so be careful when pouring it down your sink drain.

Make sure to immediately wipe up any drops that may linger on your sink’s surface in order to prevent any staining or marking.

Materials needed:

  • Drain cleaner
  • Gloves
  • Hot water

Step One: Pour in Drain Cleaner

Before you begin, read the instructions on the bottle of drain cleaner. Do not mix with any other chemicals according to the label. Put on your gloves and pour the drain cleaner down your drain. Be sure to aim directly for the drain and to not drip on your sink.

Step Two: Wait

Most drain cleaners need 30 minutes to an hour to fully dissolve the sludge or slime that may be clogging your sink drain. As always, follow the instructions on the bottle. Do not run water down the drain during this time.

Step Three: Rinse out Drain

When the waiting period is over, turn on hot water and allow it to run for a while according to the bottle instructions. This action will flush out the drain cleaner and remove any of the remaining black sludge from your drain.

Method 2: Vinegar, Baking Soda and Boiling Water

How it Works:

Vinegar and baking soda together create a fizzing action that loosens grime and dirt. Vinegar also has antibacterial qualities. Combined with boiling water, these ingredients can clean out any lingering mess that may be plaguing your sink drain.

Materials needed:

  • Boiling water
  • White vinegar
  • Baking soda

Step One: Put Water on to Boil

Put a pot of water on the stove or in the microwave and allow it to begin boiling.

Step Two: Shake Baking Soda down the Drain

Dump the baking soda down the drain that has the black slime in it. You can use an entire box of baking soda for really tough clogs. Don’t worry if it piles up, it will be washed down later by the boiling water.

Step Three: Pour Vinegar into the Drain

Pour a small bottle of white vinegar down the drain. Once it hits the baking soda, it will start bubbling and fizzing, effectively loosening the sludge that is clogging the drain. Leave this mixture to sit in the drain for a few minutes while the water finishes boiling.

Step Four: Pour Boiling Water into the Drain

Carefully, take the pot of boiling water off the heat and pour it directly down the drain. This flushing action, combined with the baking soda and vinegar, should cut through the clog and push it down the drain. Wait for a few minutes before running room-temperature water down the drain to test.

You may repeat this process once or twice. If this method does not completely clear the black sludge from your drain, consider using a commercial drain cleaner.

Method 3: Clear Sludge from Pipes Manually

How it Works:

If neither natural nor chemical remedies have worked, it’s time to take apart the pipes and manually clear them out. Though this is the most unpleasant method on this list, it could be the most effective.

Materials needed:

  • Tools for unscrewing pipes
  • Handyman know-how
  • Wire hanger and/or bottle brush
  • Plenty of paper towels
  • Trash can

Step One: Turn off Water Supply

It’s very important that you turn off the water supply before attempting anything with the sink pipes. Gather your tools and position yourself under the sink.

Step Two: Dismantle Pipes

With your tools and instructions for your particular sink, unscrew pipes under your sink. Usually sludge collects in the P-trap, which can cause unpleasant odors. Unscrew this and look inside.

Step Three: Clear Sludge or Clog

When you find the source, use the wire hanger or the bottle brush to manually clean it out of the pipe. Empty the mess into the trash can, and keep your hands and pipes wiped clean with paper towels.

Step Four: Reassemble Pipes and Test

Put everything back together carefully. Turn the water back on. Test to see if that cleared the slime from your drain and if everything is running smoothly. If so, congratulations!

If your sink is still clogged, the problem may be further down the drain line and require a professional plumber’s assistance.

Note: When in doubt, call a professional.

Preventing Black Slime In the Kitchen

Always dispose of cooking grease or oil by placing it in the trash or pouring it outdoors where it can break down naturally.

The fats in grease do not break down within drains or drain pipes and tend to collect over time. Vegetable and animal fats are the number one source of drain clogs.

Keep this in mind when cooking with either, and wipe out your pots and pans with a disposable paper towel before washing them. Doing so will reduce the amount of grease that can contribute to black sludge in your sink.

Preventing Black Slime In the Bathroom

Hairballs are not just for cats, they can happen to humans too, especially in sink drains. To prevent hair from collecting in your drain, brush or comb your hair before using your sink.

If you see any stray hairs in the sink, gather them with a paper towel and throw them away. Do not wash them down the drain. Soap scum can also bind the hair together and create slimy sludge in your sink drain.

Always keep your sink clean and free of soapy residue. Run the water for an extra second or two after washing your hands to ensure the drain is completely clear of residual soap.


Try performing daily mindfulness and maintenance to prevent black sludge from building up in your sink drains.

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