How to Clean Lava Rock

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Lava rock has multipurpose use. For example, the unique structure of lava rock makes it a decor piece at home. But how do you clean it? Here is a breakdown of how to clean lava rock.

How to Clean Lava Rock?

There is a recent explosion in the popularity of lava rock. Lava rock adds aesthetic to your simple abode. It captures dust readily than the average garden stone. As a result, you can easily rinse off the dirt in simple steps. 

Cleaning Mosses

The volcanic lava stones are porous. That’s why the water gets trapped in the pores leading to mosses. Many people adore the mosses on lava rock, but if you don’t, then clean it off. 

Materials Required

  • Copper sulfate
  • Iron Sulfate
  • Ferrous ammonium sulfate
  • Bleach
  • Water
  • Protective glasses
  • Gloves
  • Garden sprayer

Step 1: Use Moss Controller

To kill the mosses and future build-ups, you can use a chemical moss controller. 

  1. Use active ingredients like copper sulfate, iron sulfate, and ferrous ammonium sulfate. Read the instruction from the packet and mix it well.
  2. Use protective gear like eyeglasses and gloves before mixing the active ingredients. Mix it outdoor.
  3. Use a garden sprayer to spray the mixture on the mosses.
  4. Leave it aside and move to the next step.

Step 2: Clean The Dead Moss

After leaving it for minutes, the mosses die. Remove the dead moss with a scrapper. You can use a garden fork for scraping off the dead moss.

  1. Rake the dead moss off the ground with a garden fork or garden rake.
  2. Rake deeply to remove the top layer or the thatch layer, which helps in feeding the moss. 
  3. After removing the thatch layer, use a pressure washer for the rock. Be careful if the rock is decorated or painted.
  4. Remove the remaining mosses manually. It will prevent the mosses from returning.

Cleaning Barbeque Residue from Lava Rock

Lava rocks are popular in barbeque as it holds fire for a longer time. Lava rock used for barbeque often get dirty and greasy. It is essential to clean it off before the next use.

Materials Required

  • Aluminum Foil
  • Barbeque Tongs

Step 1: Heat The Lava Rock

  1. Take out the lava rock when it is not enough to use. Turn it around and put the greasy part on the grill grate.
  2. Cover it up with aluminum foil, so it captures the heat evenly.
  3. Turn on the barbeque and leave it for 30minutes. The grease and gunks will come out easily. When it is dome off the barbeque.
  4. When it cools down, open the aluminum foil, and you are good to go for the next grill.

Cleaning Mold

One of the things that can damage the lava rock is mold. Mold can damage the integrity of the rock’s top layer. The growth of mold near vegetation can harm the plants.

If the lava rock is kept in a moist space, then it should be cleaned regularly.

Materials Required

  • Cutters
  • Disinfectant or fungicide
  • Pressure washer
  • Gloves and eyeglasses as protective gear

Step 1: Clear The Area For Sunlight

Lack of light lets the mold grow. Sunlight in the area will prevent the growth of the mold. 

  1. Cut off extra twigs and branches near the flower bed. 
  2. Next, use tree trimmers for high branches and cutters for low-lying branches.
  3. Finally, apply fungicide on the mold to kill the mold. Applying it won’t cause harm to the plants and trees. 

The procedure will help in killing the mold and prevent mold build-up. 

Step 2: Remove Moisture Source

Moisture can cause molds that can harm the plants nearby. Removing the molds on time can save the plants.

  1. Remove the pipes connected to the flower bed. It will cut off the moisture source.
  2. Promote drainage and spread the water source to dry spots.

It will prevent mod build-up in the future. Alternatively, you can use a pressure washer or ask for cleaning services to do that.

Here is a video guide you can follow. 

Cleaning Algae 

Algae grow where there is an excess nutrient. Lava rock kept in aquariums or near water bodies has a high chance of growth of algae.

Here is the breakdown of steps to clean algae from lava rock.

Materials Required

  • Spray bottle
  • Bleaching powder
  • Bowl of water
  • Sandpaper
  • Paper towels

Step 1: Use Paper Towels

  1. If you have lava rock in the aquarium, then use a paper towel to dry it off.
  2. If you do not have a paper towel at home, use a newspaper to soak the excess water.
  3. Next, use a clean toothbrush to remove the layer of algae.

Drying off the water will ensure that there is no grime accumulation on the lava rock.

Step 2: Make a DIY Cleaning Solution

The algae build-up on lava rock can be cleaned at home with a DIY solution.

  1. Mix equal parts bleach and equal parts water.
  2. Use gloves and a mask and do this procedure in a well-ventilated room.
  3. Spray the mixture on the rocks. If you have decorated the rocks with paint, then apply it on one rock and test if the paint coming off or not.
  4. If it looks alright, apply the solution to the rest of the rocks. Leave it for 15mins. 

When bleaching is mixed with water, it forms chlorine gas that helps in killing the algae.

Step 3: Stop the Water Source

Algae grow when there is an active source of water or moisture on the surface of the rock. Therefore, stopping the water source will kill algae.

  1. If you don’t have bleaching powder at home, keep the lava rocks on a towel and naturally let it sun dry for 24 hours. 
  2. When no more moisture is left on the rock, it becomes easier to clean. The algae get nutrients from water and moisture in the air. When the surface starts drying, the algae dies.
  3. Use sandpaper or garden rock and scrub the surface of lava rock vigorously. 

After cleaning it properly, put the clean rocks in the fish tank. Algae can lead to eutrophication which can harm the aquatic life in the aquarium. 

Maintenance of Lava Rocks

According to old times, ‘an ounce of care can save a pound of time’. It means if you prevent the rocks from getting dirty in the first place, you can save time and money.

A red lava rock

Lava rocks require very little maintenance; clean up regularly to prevent moss or algae build-up.

  • Do a routine check of the rocks; if there is any weed growth, pull it off. It will promote sunlight and airflow in the rock.
  • Clean the leaves and debris from rocks as it promotes the build-up of molds. Use a leaf blower or brush to clean debris.
  • For aquarium lava rocks, put them under the sun when you change the water for fish. This will kill the algae, and after cleaning it properly, you can put it back in the aquarium.
  • Clean the dust and dirt from the rocks by pressure washer. This will help thorough cleaning of crest and crevices of the rock.

Here is a lava rock care manual that you can refer to to maintain the lava rocks better. 

Benefits of Lava Rock

Lava Rock for Grilling

Lava rock is safe to cook, and it improves the performance of the fire pit. Lava rock can radiate more heat into the gas burner, which reduces the grilling time. 

Lava rocks help in even heating of the grill that induces even cooking of the meat.

Lava Rock for Aquarium

Lava rock provides an ideal environment for fishes in the aquarium. Lava rocks are extremely porous that allows water to pass through and diffuse in the rocks. 

This creates an anaerobic environment inside the rocks. Inside the rock, the denitrifying bacteria consume the nitrates and release oxygen.

Thus, it helps in oxygen flow in water that benefits the aquatic life in the aquarium.

Lava Rock for Garden

Lava rock brings a pop of color to the garden aesthetic. Putting lava rock near flower beds will prevent soil erosion and allow nutrients to seep through it.

Keeping lava rock in the garden drastically lowers the water requirement for plants, as the lava rocks capture the moisture that can benefit the flower plants nearby.

Frequently Asked Questions

Do Lava Rocks Make Water Cloudy?

No, lava rocks do not make the water cloudy. If the water becomes cloudy, it can be due to red and green algae in the rock. Put the rock out and wash off the layer of algae, and the rock will be fresh like new and ready to be reused.

Should I Clean Black Lava Rocks?

Yes. Lava rocks are porous in which dirt and grime get accumulated. You can wash it by spraying water in the opposite direction of pores. It has good drainage; the water will drain, and the dust will be cleaned. 


Lava rocks are a great addition to indoors and outdoors. The volcanic rocks are glamorous and functional. Cleaning it from time to time will prevent from breaking of the rock.