Everything You Need to know about Lava Rocks for Aquarium

Lava rocks are a popular decoration for both fresh and salt-water aquariums—homeowners like the rugged appearance, porous surface and durability of lava rocks. Lava rocks can be purchased at pet stores and some home and garden centres in various sizes and shapes. Though these properties make it an ideal decoration, they also provide an environment where algae, fungi and bacteria can quickly grow. Before adding any decorations to your aquarium, it is vital to make sure the rocks are free of bacteria, funguses and algae. It is also essential to clean your new lava rocks before placing them in your aquarium tank.

How to Prepare Lava Rocks for an Aquarium

The lava rock aquarium setup process is straightforward to do. It usually does not take more than a couple of hours to set up this aquarium decoration. Here is a step by step process on how to prepare lava rock for an aquarium:

Wash Lava Rocks:

Rinse all rocks thoroughly with clean water to remove any debris and dust. Be sure the water is free of chemical cleaners or soaps that damage your aquarium environment.

Boil Lava Rocks: 

Boiling the rocks is an effective way to kill bacteria on the rock surfaces. Place washed lava rocks in a large saucepan and cover them with cool tap water. Bring the rock to a boil, then turn the heat down to medium. Allow the lava rocks to simmer for 10 minutes. Drain them, return them to the pot and cover them with water again. Bring this second boil to a simmering point again; allow the rock to simmer for another 10 minutes.

Rinse Again:

Rinse all rocks thoroughly with clean water to remove any debris and dust. Be sure the water is free of chemical cleaners or soaps that damage your aquarium environment.

Allow Rocks to Completely Air Dry: 

Place rocks on a towel; if you add natural plants, make sure they are placed away from any direct sunlight. Allow them to air dry completely before you put them in your aquarium.

Turn Over Rocks: 

Before adding rocks to an established aquarium:

1. Turn the rocks over and examine the bottom for signs of growth.
2. Turn half of each rock over to ensure a thorough examination.
3. If you notice any suspicious-looking areas developing on the bottom, discard those rocks.

Add Rocks to the Aquarium: 

Once you are sure your lava rocks are clean, fill your aquarium with water and place them along the bottom. Follow recommended dosage instructions for any additives added to the rock.

Benefits of Lava Rocks for Aquariums

There are several benefits of lava rocks for aquariums. Some of them are mentioned below.

Lava Rocks Lower Nitrate Levels:

Lava rocks can be used in the aquarium to help remove nitrates from the water. The porous surface of lava rock acts as a breeding ground for nitrifying bacteria, which eat nitrate and other toxins in your aquarium.

Space-Saving Decoration:

Lava rocks can be used in aquariums of any size. They typically come in small, medium and large sizes, so they are ideal for beginners who may not have a large amount of space or money to spend on their first set of decorations. They are also helpful when setting up the aquarium in an office or another area with limited floor space.

Lava Rocks Provide Caves for Fish:

Fish like to hide in dark, secluded areas to rest or escape from other fish. Lava rocks provide many caves and hiding places for your fish to enjoy.

Lava Rocks Provide a Natural Look:

The varied sizes and shapes of lava rocks give your aquarium a natural, earthy appearance. They do not have sharp edges so they won’t tear the fins or scales of fish.

Improves Bio-Diversity:

Adding a variety of large rocks to your aquarium can provide a good home for many microorganisms, which promotes a healthy aquarium ecosystem.

Improves Water Circulation: 

Lava rocks are porous, improving water circulation by creating more space for water to move through. This increases oxygenation and helps purify the aquarium’s water.

Prevents Algae Growth:

Placing lava rocks in your aquarium can prevent algae growth by creating obstacles for light penetration. The areas under the rocks will be dark, discouraging algae from growing there.

Lava Rocks Promote Plant Growth:

Plants need a lot of available nutrients and water to stay healthy and thrive. Like many other decorations, lava rocks can increase the available nutrients in your aquarium. The porous rocks also serve as a hard surface on which plants can anchor themselves.

Lava Rocks Decrease Water Temperature:

The dark color of lava rocks absorbs heat, which helps cool the water. For tanks located outdoors or near windows, this can help prevent sudden temperature changes.

Lava Rocks Improve the Aesthetics of Aquarium: 

The types of rocks you use in your aquarium can significantly impact its aesthetics. Lava rocks come in various shapes, colors and textures to fit any home décor or fish tank. They add variety and interest to an otherwise simple display.

Types and Varieties of Lava Rocks

There are many types and varieties of lava rocks you can choose from. We will discuss some of them below.

Black Lava Rock:

Black lava rock is jet-black in color and very smooth on its surface, without any rough edges or jagged peaks. It provides a sleek, modern look that looks great with any tank. It is also easy to clean and maintain because no dirt or gunk accumulates on the surface.

Gray Lava Rock:

Gray lava rocks are light-colored and smooth with few wrinkles and crevices, which makes them very easy to clean. They provide contrast against dark sand and gravel, making them a good choice for your tank’s substrate.

Green Lava Rock:

Green lava rocks come in shades of brownish-green to forest green. They typically have more wrinkles than grey or black lava rocks. The notches and indentations can trap dirt and sand, so it is best to rinse the rocks off before placing them in your aquarium.

Pink Lava Rock:

Pink lava rocks come in shades of brownish-pink to pale pink, and they often have a rough texture with many cracks and crevices. These can trap dirt and sand, so it is best to rinse the rocks off before placing them in your aquarium.

Yellow Lava Rock:

Yellow lava rocks come in different shades of brownish-yellow to bright yellow. They often have a rough texture with many cracks and crevices. These can trap dirt and sand, so it is best to rinse the rocks off before placing them in your aquarium.

Things to consider for buying lava rocks

You can keep in mind some tips before buying lava rocks for your aquarium.

Don’t Worry About Size but Shape:

When buying lava rocks, make sure to stay away from pointy edges or sharp corners that could hurt your fish. However, you can disregard their size because lava rocks are pretty heavy, so fish will not easily displace them.

Pick Lava Rocks with Less Pointy Edges:

Lava rocks with fewer pointy edges are easier to clean, so it is recommended that you choose these types of rocks. Sharp edges also make it more likely for the rock to shift around the tank, potentially causing injury to your fish.

Lava Rocks with Less Dust are Easier to Clean:

You can save your cleaning time and water by purchasing the lava rocks with lesser dust. The more porous rock is, the easier it is to clean. So, for even easier cleanup, make sure you buy lava rocks that are branded as “cleaner.” A cleaner rock will have little to no dust or debris on them when purchased from a pet shop.

Frequently Asked Questions

How do you identify lava rocks?

Lava rocks are typically black, grey, green, or yellow rocks. The colors of the lava rock give an idea of its texture. Light-colored lava rocks have smooth surfaces, while dark-coloured lava rocks have rough surfaces.

How thick should lava rock be?

Lava rocks should be at least 3 inches thick. Thinner pieces of lava rock can crumble under the weight of gravel and other heavy decors, making your tank unstable.

How long are lava rocks good for?

Lava rocks generally have a long lifespan. You can expect them to last for two years or more without showing signs of wear and tear.