What is the Brown Gunk in My Dehumidifier?

A dehumidifier removes excess moisture from your premises. The moisture it collects condenses inside it, and it is collected as water in a tank.

After using your unit for a while, you might start to notice a change in color.

This can be a bit worrying because the appliance handles water, which forms a good habitat for bacteria, fungi, and viruses.

The brownish color could even be an indication of mold.

So, what is the brown stuff in my dehumidifier? That brownish slime is a combination of bacteria, mold, dirt, and other things that you should not have in the unit. Most likely, this happens when you don’t empty the pan and leave it sitting with water for days.

If the slime is left too long in the unit, it can develop an unpleasant, rancid odor. It is a mixture of many things that find their way into the unit.

Does a dehumidifier need to be cleaned?

Clean your unit as frequently as you can.

You may not prevent the brown stuff from forming, but you can prevent it from building up.

To do that, just clean your unit at least once every three weeks. In addition, you should empty the pan daily to prevent mold.

When you clean it regularly, it is easier. You can use water and mild soap to clean the bucket and keep it free from germs, viruses, and allergens.

Besides, when you clean as often as you can, you can also inspect your unit for damage.

How do I keep my dehumidifier tank clean?

How do I keep my dehumidifier tank clean

You can prevent the buildup of the brown stuff by cleaning the appliance on a regular schedule. Here is a simple process for how to clean your unit:

You will need gloves

It would be best if you did not touch the mold directly. Put on gloves. If you are allergic to mold, wear a dust mask so that you don’t inhale the spores. A mask can also help if you are asthmatic.

Unplug the unit

This should be the first thing to do. There is no way you can attempt to remove any part of the unit when it is still on. Unplug it from electricity first.

Water and electricity are never good friends.

Clean the exterior

Most of the bigger dirt particles land on the surface of the dehumidifier. Wipe them off using a dry cloth.

Image of Can you put vinegar in a dehumidifier

If there is stuck dirt, you can wipe using a damp cloth. Do not spray water on the unit’s exterior to prevent damage to the internal parts.

Detach and clean the reservoir

Remove the tank from the unit and empty the water. Be careful not to spill the water. Empty the water to a drain or the sink.

Clean it using hot water with mild soap and a soft cloth. Put clean water in the bucket until it is half full. Add dish soap in the ratio of one teaspoon per gallon of water.

You can loosen the debris by stirring the water. In addition, you can scrub the tank using a soft-bristled brush to remove mold. You can use a bottle brush to reach the corners.

Rinse, dry and replace the reservoir

Empty the tank and rinse it with clean water. After that, dry it using a clean, dry cloth.

Replace the reservoir and return the tank to the dehumidifier.

Clean or replace the filter

The filter absorbs most of the dirt. Follows the manufacturer’s instructions to clean or replace it. If it is reusable, check if it is too worn out to need replacing.

If it is still good to use, vacuum it to remove the grime, and then soak it in a solution of warm water with mild soap for about 10 minutes. Remove and dry it off, and then replace it with the unit.

Plug the unit back into a power supply.

How to prevent brown slime in dehumidifier

How to prevent brown slime in dehumidifier
Dirty dehumidifiers have brown slime in bucket

Prevention is better than cure, so they say.

Therefore, how do you prevent the formation of the nasty brown stuff in your unit?

There are a few things to do:

When you want to store the unit, empty it, clean it, and dry it. This will prevent the formation of mould when in storage.

When in use, you might not be able to empty the tank daily. There is a way around it.

Just connect the dehumidifier to a drain. This way, the water will not go to the tank but will drain automatically.

If there is no stagnant water in the tank, mold will not form.  However, you will need to clean the draining hose using white vinegar at least once every three weeks to kill mold.

Can you put vinegar in a dehumidifier?

Indeed, you can!

It is recommended that you disinfect the tank using white vinegar. If the tank has mold, you can disinfect it using white vinegar.

To do this, put water and vinegar in the tank in equal quantities. Scrub using a soft brush.

Let the solution stay for about 30 minutes, and then rinse and dry the reservoir.

Some people disinfect the tank using bleach to kill the mold. If you do this, make sure you rinse the tank thoroughly until there is no smell of bleach.

One more thing, though: never mix bleach with white vinegar. That would produce a poisonous gas that could harm your family.

What are the black flakes in my dehumidifier?

Brown slime composed of microbes, pollen, grease, mold, and other indoor air contaminants, is not the only thing you will see. If you do not clean your dehumidifier as recommended, it is possible to see black flakes in the bucket.

What are these? These are scales, mixed with mold. It can also be combined with other indoor contaminants. You will notice these contaminants in the dehumidifier water. That’s why it is not advisable to drink dehumidifier water.


What is the brown stuff in your dehumidifier? Now you know!

Whatever it is, you can be sure it is not good, and you don’t want it there. Therefore, prevent its formation or clean it out if you see it.

Dehumidifiers and humidifiers are always in contact with water, so they breed black toxic mold easily. To prevent this, clean these appliances regularly, depending on their usage.

If you use the dehumidifier daily, clean it three times a week. Also, change the filters as recommended by the manufacturer.

There is a dehumidifier warning symbol that will alert you of the need to clean or change filters.

You might love the Pro Breeze Electric Dehumidifier that you can buy on amazon.com.