Can I Use Outdoor Gravel or Rocks in an Aquarium

Rocks and gravel are the most exciting materials for landscaping aquariums. We can decorate our aquarium using rocks and gravel, and rocks and gravel are not only decorative materials.

We can also plant live plants in gravel. A fine-planted tank with rocks and gravel can provide an attractive look. Gravel and rocks also provide a habitat for aquatic creatures.

In this care guide, we will learn how to choose good rocks for aquarium, unsafe rocks for aquarium, How to clean them, and many more. Let’s continue the Can I use outdoor gravel or rocks in an aquarium.

Can I Use Outdoor Gravel or Rocks in an Aquarium
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Why do we need gravel or sand or rock in our aquarium?

A new aquarist may ask, Why do we need gravel or rocks? Primarily rocks and gravel are used for only beauty purposes. But there are some other important factors, why should put gravel and rocks.

Especially when we want to put live plants in our aquarium, gravel will help the plants to anchor the plant at the bottom of the tank. The roots will grow in the gravel we put in the aquarium.

Plants are a great addition to any aquarium. Not just only do they give an aesthetic look to our aquarium, but they also provide an additional oxygen source to an aquarium.

It also helps to balance the water chemistry.

How do we test outdoor rocks for an aquarium?

We shouldn’t put any rocks and gravel before testing it if the rock or gravel contains calcium, Which can change aquarium pH. If the water pH goes too high, this will harm our fish in many ways.

So it is best practice to test these outdoor rocks before putting them in an aquarium. We will discuss two methods of testing the stone. But before that, we should thoroughly clean these stones.

Make sure there aren’t any dirt, girt, and any contaminants.

After cleaning, we can use white vinegar or any acidic substance to test if the stone has calcium or not.

Put White vinegar or any acidic substance on the rock. If the substance forms foams or fizzes, we can’t use the stone or rock.

Unsafe rocks for aquarium
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The meaning of foaming or fizzling is an indication that the rock has calcium on it.

The other testing method is, take some water from your aquarium and put it into a bucket. Now put the stone or rock that should submerge into the water.

Before putting the rock or gravel, we should test the water parameters like hardness and pH of the aquarium.

Now leave the submerged rocks or gravel into the bucket for a week. After a week, retest the water parameters like hardness and pH. If the water parameters increased significantly, we should not use that rock or gravel.

Rock that is safe to use in aquarium

We can also use lava rocks as long as we remove any shape edges from the rock. Some species of fish, like Corey species, have extremely sensitive barbels, and we don’t want to harm the fish.

Sandstone can also be used, but we should test it before putting it into an aquarium. This stone contains some limestone minerals, and we should make sure that it has zero traces of limestone.

Here is a list of safe rocks that we can use in the aquarium:

  • Granite.
  • Quartz.
  • Slate.
  • Lava rock (remove the sharp edge)
  • Onyx and ground glass.
  • Sandstone (Test before using, as it may contain traces of limestone.)

We should always test before putting any rocks or gravel in an aquarium. Many rocks and gravels have a mixture of minerals, even in the same stone.

Unsafe rocks for aquarium

Should avoid every rock or gravel containing calcium. We also should not use sharp-edged rocks as they can harm the fish. Here is a list of rocks that consider as unsafe for aquariums:

  • Shells or crushed coral
  • Limestone
  • Geodes
  • Marble
  • Dolomite

How can we clean river rocks for an aquarium?

Here are a few ways that we can clean the river rocks:

Scrubbing with a brush

We can clean organic matter, soil, and algae through this method. Scrub the rock using the brush under the running water.

Soaking in distilled water

Some hard minerals can dissolve the rock by soaking in distilled water. Though, if the stone is loaded with limestone, soaking in distilled water will not help.

Bleaching rock

Bleaching will loosen organic matter. Once the bleaching is done, we need to remove the remaining bleach. We can wash the rock with a few buckets of water or let the rocks dry in the sun.

How much gravel do we have to put in our aquarium?

We should put 2-3 inches in depth for gravel. They are typically sold in weight.

The drawbacks of using gravel and rocks

There are not many drawbacks to using gravels, and the only drawback is when the blue and green algae outbreaks occur in an aquarium. It is hard to remove those algae, and sandy substrates would limit the outbreaks.

Where to find outdoor rocks for the aquarium

You can try ocean beaches and lakefronts, in dry wash beds, or along the banks of the streams and rivers. Avoid collecting stones from underwater locations, especially in protected environments.

Removing those stones can disturb native habitats that wild fish and plant life depend on.

Remember to test the rocks and gravel before putting them in the aquarium.

Hey, I am Shuvradeb Biswas a content writer. Fishkeeping is my hobby. There are many problems I faced during my first fishkeeping. So, I made the blog to help new fishkeepers.

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