What is a Rock Salt Dehumidifier and How To Make One

High humidity can be uncomfortable for anyone. Perhaps the most effective and efficient solution to reduce indoor humidity is by using a dehumidifier. However, it can be expensive to buy, operate, and maintain. Fortunately, there are many natural ways you can help reduce humidity. Using rock salt and other household staples, you can make your own dehumidifier. 

While they may not be as effective as electric dehumidifiers, they are much cheaper to make and easier to maintain. You can place these DIY dehumidifiers almost anywhere in the house, but they are particularly useful in tiny, enclosed spaces. All you really need is a large enough container. If you have your items ready, we’ll teach you how to make your own dehumidifier below.

Why You Need to Control Humidity

First, you must understand what humidity is and why it’s important to maintain proper indoor humidity levels. The relative humidity we measure is the percentage of water actually present in the air compared to the maximum amount it could hold at a given temperature. The ideal range of relative humidity is from 30% to 50%.

Higher relative humidity tends to make the air temperature feel hotter, making you feel uncomfortable because perspiration cannot evaporate into the already saturated air. Aside from causing discomfort, high humidity creates a perfect environment for mold growth. Touching mold or inhaling mold spores can trigger allergies and lead to allergy-induced asthma attacks. High humidity is also ideal for dust mites, another common allergen.

Furthermore, mold and mildew can grow on almost any moist surface and spread as it feeds on the material. If left unattended for too long, this can damage walls, furniture, soft furnishings, and carpeting. Excess moisture can also damage fabrics, food items, and other personal belongings, as well as your house structure. It can lead to paint peeling off, wood rotting, and metals rusting. 

To prevent these problems, it’s critical to maintain humidity within the recommended range. If the humidity drops too low, it can also lead to a different sort of problems that can affect your health and your house.

Signs of Humidity Problems in the House


It can sometimes be difficult to determine when you have humidity problems until it has already caused damage. Before it becomes too late, here are some common signs of humidity in your home that you need to watch out for.

First, check the humidity levels with a hygrometer or a similar device to measure relative humidity. If it is often around 60% or higher, this is surely a problem. If you live in a region with a humid climate, you can also expect high indoor humidity. Humidity levels may be higher at certain times of the day, but if it rarely goes down to 40–50% RH, then it may be a serious problem. If you or anyone in the house suffer allergic reactions, this could be a sign of dust mites and mold due to high humidity.  

Condensation or fog on windows and other colder surfaces is an early sign of too much moisture in the environment. It happens when damp air comes into contact with a colder surface, such as windows, walls, glass, or other metal surfaces. Condensation is common in the bathroom or basement.

Small storage spaces, especially tightly sealed metal safes are prone to excess moisture. If you store food items and other organic materials like fabric and paper, the moisture gets trapped inside, causing excess humidity. 

More severe humidity can lead to mold and mildew growth. Mold may be hard to spot right away since they like dark and damp places that aren’t always visible such as under the sink or toilet, or beneath the carpet or rugs. Mold can appear in different colors, but are usually dark brown and greenish spots, or fuzzy, white powder. If you notice a musty smell coming from the attic, basement, or crawl space, then this is a sure sign of mold growth due to high humidity. 

In more extreme cases, you may find water stains on your walls and ceilings. You might also notice cracks in drywall or gaps between the floor and baseboard. In case a puddle of water starts to pool in one area, like a corner in your basement or crawl space, it’s best to consult a licensed contractor to fix any leaks or cracks or any other source of moisture and find the right solution before you purchase a dehumidifier.

How to Make a Rock Salt Dehumidifier at Home

Rock Salt made form Dehumidifier at home

While electric dehumidifiers are often the most effective solution to remove excess moisture in any room, they can be costly to buy and to operate. They also require a lot of maintenance. 

The good news is, you can also use a natural dehumidifier to absorb moisture from the air with little effort from you. Some of these items you can find right in your kitchen. Perhaps the easiest alternative dehumidifier option is rock salt or table salt. It is a natural desiccant or a hygroscopic material that absorbs water vapor from the air around it. 

To make your own rock salt dehumidifier, get a large bowl or bucket you don’t use. Drill small holes in the bottom where the absorbed water can escape through. Fill this container with how much rock salt can fit and place it on top of another similar container where the water can drip down. Place it in a corner of the room or anywhere you need and that’s it! Just remember to check the containers at least once a week. When the bottom container is full, throw the water away, and refill the top with rock salt.

Other Alternatives for Homemade Dehumidifiers

There are also a few other natural dehumidifier options in alternative to rock salt. You can use the baking soda, coffe creamer or whitener, and charcoal you can find at home. Or, find some calcium chloride or silica gel.

Baking Soda

Another common household product you can use as an alternative dehumidifier is baking soda or sodium bicarbonate, which can also help neutralize odors. To make your dehumidifier, simply place a good amount of baking soda in a bowl or any open container and then place it in the humid space. Check it every few days and stir the powder when clumps start to form. While it’s not the most effective moisture absorber, it’s good for tiny spaces with strong odors like the kitchen and bathroom.

Coffee Creamer

Non-dairy creamer or coffee whitener can also help absorb excess moisture in the air. Fill a large bowl with the powder and place it where it’s needed. When the coffee whitener powder hardens, just replace the contents of the container.


This one also has a lot of benefits, including absorbing moisture and eliminating odors. Just place a charcoal briquette in a bowl and place it where you need it. Charcoal is mostly used in bathrooms, closets, kitchens, and even inside refrigerators.

Calcium Chloride

One of the most common desiccants used commercially is calcium chloride, which you can purchase from drugstores and hardware stores. Just place a few cups of the small white beads in a bowl, or a sock, or lycra stocking to hang. Place a bowl under it to catch the liquid that the crystals dissolve into. Calcium chloride (as well as other salt crystals, potassium chloride, and sodium chloride) is also used in moisture absorbers like DampRid. 

Silica Gel

Silica gel is what you can find in tiny packets with a DO NOT EAT warning inside boxes or bottles of packaged goods. Instead of throwing them away, you can save and reuse them as a homemade dehumidifier. Silica gel can absorb up to 40% of its weight in water, which means 100 grams of this material can remove as much as 40 ml of moisture from the air. Just drop a packet or two into your gym bag, or place them in a container in your kitchen cabinet or closet. You can also purchase new packets from hardware stores. 

Silica Gel

Tips to Help Reduce Humidity

Instead of simply removing moisture, you can prevent humidity in the first place with a few easy steps.

The first thing you can do to reduce indoor humidity is by introducing fresh air to the indoors with proper ventilation. During the day, open your windows and doors to let the cool air dry out any excess moisture. Although, note that this can only be effective if the humidity level outside is lower than the humidity inside. 

If you can’t open your windows, run your fans to at least circulate the air inside. The added airflow prevents moisture from accumulating and speeds up evaporation. You can replace the damp indoor air with fresh outdoor air by using an exhaust fan instead of opening windows. Running an air conditioner can also help reduce humidity but only to a certain level without racking up your cooling bills.

Taking a hot bath or shower forms a steam and adds to the humidity in the bathroom and adjacent rooms. To minimize the moisture released into the room, try to keep your showers or baths shorter and colder if possible. Likewise, cooking forms steam and smoke in the kitchen, contributing to the humidity. Open the windows or turn on the exhaust fan during and after using the bathroom or kitchen to keep excess moisture and odors out.

Avoid hanging wet laundry inside the house as the water evaporates into the air and increases moisture levels. Letting your clothes remain damp indoors can also cause musty smells to stick to the cloth fabric. If you can’t hang them outside, you can also use a dryer or fan to speed up drying.

Lastly, in case there’s any standing water from small leaks under sinks or due to cracks in the basement foundation, make sure to get them fixed as soon as possible. 


Before you make your DIY salt dehumidifier, it’s critical to find the source of humidity and remove it. If there are small cracks in your walls, warm air can seep through them and enter your home. If you have any water damage such as leaks or burst pipes, this can cause extreme humidity that even an electric dehumidifier cannot solve. Homemade dehumidifiers are ideal only for tiny spaces prone to moisture, including kitchen pantries and other storage areas.