Best Rocks For Freshwater Aquariums 2022 – Reviews & Buyer’s Guide

1. 12″Coral Base Rocks 2. Cichlid Stones 3. Penn Plax


If you have been searching for Best rocks for freshwater aquariums, you have arrived in the right place. We have brought together a curated list of the top-rated rocks that you can use in aquariums to create a beautiful ecosystem. Well, before we can move on to that list, there are certain things that you must know.

The rocks for freshwater tanks should not be affecting the pH balance of the water. You are well aware of the fact that Freshwater means soft water, and adding any unwanted rocks to it would change the balance, resulting in difficult terrain for the fish and other creatures. So, it is advisable to select the right kind of equipment depending on the type of ecosystem you have set up in your aquarium.


Several factors need to be considered for selecting the Best rocks for freshwater aquarium. Read them carefully and move on to the list to select one.

Factors To Consider While Buying Best Rocks For Aquarium

1. Appearances

While you are searching for good rocks, look for the most appealing ones. These include red, pink, blue, and purple colored ones since these are known to be mature and contain natural algae colors. These rocks will look stunning and would create an amazing visual appearance to the fish dwelling in your aquarium.

Make sure to not go for rocks that are black colored or slimy in texture. It might be possible that they are coated with dead substances and may ruin your entire ecosystem.

2. Cleanliness

The rocks that you would be choosing should keep the tank unaltered in terms of odor and waste. Some rocks rot easily in the water. So, before selecting any, make sure to smell each one of them; if the smell is rotten, you need to eliminate it as it can alter the composition of water.

Some creatures often start crawling or living in old rocks. This may pose a threat to other animals in your tank. Eliminate these rocks to keep the tank clean at all times.

3. Best Value

The first thing you need to determine is your budget. The money that you will spend will decide how you are going to filter the rocks from the list. Now, there are many options available that are cheaper but not as good as the ones which are a bit costly. So, if you are willing to add some extra bucks in your budget, go for the best option or at least mid-range rocks.

4. Size

You will find multiple sizes of the rocks available for each variety. It will depend on the tank size, and how much space you have left for the rocks to be decorated inside the tank. It is advisable to choose mid-sized rocks or smaller ones, especially if you have a tank with less than 10-gallon capacity. Along with the filter, plants, and other decorative products, you will not have a lot of space for the rocks.

Big sized rocks will fill up space, and the fish may not like it, especially the Betta fish. There should always be ample space for the fish to swim around and have a comfortable stay inside the water. Overdecorating will be a huge disadvantage.

Top 15 Best Rocks For Freshwater Aquariums 2022

1. Nature’s Ocean 12-Inch Coral Base Rocks

best rocks for freshwater aquariumThis coral Base rocks by Nature’s Ocean is one of the best rocks you can choose from with amazing features. It is 12-inches in size and weighs around 40 pounds. Well if you wish to have smaller pieces, you will have to go through a hectic process, so it isn’t worth it.

Now, the very first thing that you must do once you receive the package is to rinse it very thoroughly. You will find this rock very dusty. Not washing the rocks would be a terrible idea.

The package contains multiple sizes of rocks from large to small pieces. Well, we would recommend to use it for bigger tanks as the smaller pieces could also be huge in size overall.

These coral base rocks are perfect for Coral Farming, Culturing Live Rocks & Growing Live Coral. They are natural rocks and so would fit in perfectly with the tank’s ecosystem without changing any composition of the water. Moreover, it acts as a natural porous biological filter, Free of Biofilm & perfect for aquascaping.

This is the best-valued rock for aquariums and has been well soaked in water to prevent leeching in the future. In terms of the price range, it could be a little expensive overall. There are a lot of options that you can choose from which are much lower in price.


  • Good for large tanks
  • Perfect for decoration
  • Acts as a natural biological filter
  • Prevents any leaching in water
  • Does not affect the composition of water


  • Not ideal for small tanks
  • Needs thorough cleaning before use.

2. Underwater Galleries Cichlid Stones

Underwater Galleries Cichlid StonesThe Underwater Galleries Cichlid is one of a kind rock for your freshwater aquarium. The package contains six large stones of three different versions and four medium Cichlid Stones of two different versions. Each stone has a spacious interior mainly designed for the tank dwellers.

These rocks are molded with utmost perfection and care. Also, every piece is hand-crafted, providing a natural look for the aquarium.

The best part is that these rocks are eco-friendly and do not displace any amount of water from the tank. Since these are hand-glazed stones that are heated for 2100 degrees, it is advisable to handle them with care.

Make sure you do not put too much strain on these rocks as you may lose the main texture and nature of the rocks. The color of the rocks is more of a rugged-gray, that has been carefully made. Once it is out from the package, you need to clean it very gently before use. These rocks are for small fishes since the openings are only 1″ inch wide. Big fish may not fit inside conveniently.

To keep the tank clean, make sure to clean the rocks from the inside regularly, since the fishes may have left out the waste while hiding inside. These rocks are costly and could be a little too much than your budget.


  • Keeps the water from being displaced from the tank.
  • Eco-friendly and lightweight
  • Durable and strong built
  • Hand-crafted
  • Serves as a right hiding spot for fish


  • Expensive
  • Not very suitable for big fish

3. Penn Plax Stone

Penn Plax StoneThe Penn Plax Stone is a stunning freshwater Aquarium stone that has a beautiful shade of black and grey color. The package contains three small stones, three medium stones, and two large stones.

The shape of the rocks is perfectly cut, giving a realistic granite look. If you have a small tank such as less than 10-gallons, you can stack these rocks in them too.

These rocks have multiple holes carved into them to provide a hiding or a resting place for small fish. All the rocks are different from each other and come in different sizes.

You can easily arrange them according to your needs and decorate the aquarium, making it an oceanic environment for the fish. You will notice that the large rocks that you will receive in the package have a flat top to stack other rocks on top of it and provide stability.

These aquarium ornaments come in various sizes from 2-4 inches high. Also, they weigh only 11.4 pounds which is super light. The Penn Plax stones not only provides a stunning visual interest for humans but also act as a hideaway and pass-through passage for fish. Such rocks are suitable for both Freshwater as well as Saltwater aquariums.

You will be thrilled to know the price of these rocks. They are very cheap and affordable for people with low budgets. Not only do they have a low price range, but also amazing features making it a perfect choice. You can also buy additional stones separately along with this kid to create larger displays.


  • HIgh-quality granite looking rocks
  • Affordable and cheap
  • Very durable and safe to use
  • Super lightweight
  • Best suitable for small fish


  • Not a good choice for big fish
  • Needs brushing as some stones are sharp on the edges

4. Oupeng Pebbles Polished Gravel

Oupeng Pebbles Polished GravelIf you are looking for the cheapest and the most affordable option for your aquarium, well this is one option. These river rocks have been naturally polished and come in a variety of colors such as brown, whites, and black rocks.

These pebbles help to retain soil moisture, provide good drainage, and do not easily deteriorate. You can use these rocks not just in your tanks for decoration but also outside in your gardens.

They have very soft and smooth edges which is why they do not hurt the feet. You may have seen these pebble in walkways, water features, exposed aggregate flooring or walls, around swimming pool areas, water gardens, ponds, and other aquariums.

Apart from giving your freshwater aquariums a nice and clean bed filled with these pebbles, you can also decorate your garden by using these pebbles as decorations. You will not have to spend a lot of money on buying plants, and it works as a perfect alternative for better visual interest.

Before using these stones inside your aquarium, make sure to rinse it off thoroughly to remove any chemicals, bacteria, fungus, algae, and parasites that may be present on the surface of the rocks. Soak the rocks in boiled water, brush off, and rinse it properly. Doing this will give it a nice shining texture. Make sure not to bring it near small children as these stones are tiny and children may attempt to swallow them.


  • Affordable and cheap
  • Lightweight
  • Multiple colors available
  • Smooth and soft edges
  • Can be used to decorate various areas


  • Size is larger than they appear in the image
  • Not enough piece included in the package

5. Carib Sea ACS00372 3 Case South Sea Base Rock

Carib Sea ACS00372 3 Case South Sea Base RockThese south sea rocks are available in various sizes and shapes for your convenience. You can use these rocks for smaller tanks as well as larger ones as well. Though the large sizes may not be perfect for smaller tanks, you can surely use the smaller pieces likewise.

After you receive the package, you may have to soak it in water or rinse it thoroughly since it may be very dusty. This will allow the nitrate levels in the water to go down naturally because of these rocks.

The South Sea Base live rock has been cured and has a thriving bacteria colony living in it. Thus, space is provided for the growth of good bacteria beneficial for the aquarium ecosystem.

These rocks are perfect for a wide variety of aquarium styles including marine, reef, saltwater fish-only setups, African cichlid tanks, and any hard water aquarium. It keeps the tank clean at all times by all-natural means. The most crucial part is that these rocks are cost-effective and affordable for you.

These rocks have been mentioned to be perfect for fish like African Cichlids, the reason being that they have a right amount of calcium in them which increases the pH level of water slightly, thus, increasing the hardness of the water. Such fish love the ecosystem and thrive well. Also, other fish may not dwell well in such an ecosystem, so make sure you are well aware of the fish you have and provide them with the perfect environment.


  • Affordable and cost-effective
  • Perfect for large aquariums
  • Removes nitrates from water
  • Provides good bacteria
  • Available in various sizes


  • Large rocks not suitable for small tanks
  • Needs thorough cleaning

6. Vitality AF135 Aquarium Decorating Cave Ornament

Vitality AF135 Aquarium Decorating Cave OrnamentThe Vitality Aquarium Cave Ornaments is one of the best aquarium rocks available at an affordable price. These caves look-alike rocks provide a spacious place for all the aquarium dwellers. Mostly for all the small fish like Betta, they can easily rest and hide inside the rock.

Moreover, the rocks are very safe and non-toxic. They do not tend to displace any water from the tanks and keep it free from any excess nitrates in the water.

Apart from setting up a natural ecosystem, it can act as a beautiful decorative ornament that looks visually stunning. It has a purplish look to it and is a single large rock. It is darker than it looks and practically glows like a fluorescent color.

If you have a small tank, it may fill up a lot of space, and you may not be able to add more rocks to it. So, depending on the size of the tank, you can certainly decide if you would like to purchase this rock. Well, the opening is big enough to accommodate a big fish too for resting and hiding.

For more details on the structure of this cave-like rock, I would recommend going through the entire description given by the makers. The color on the rocks may seem like paint, but it surely isn’t and won’t come off being in the water. It is very lightweight, no matter the size. Also, it isn’t expensive but still for just a single piece it may be a little too much.


  • Safe and non-toxic
  • Visually stunning
  • Provides spacious space for fish
  • Good for big aquariums
  • Does not affect the level of water


  • Little expensive
  • Poor packaging

7. Aquarium Gravel River Rock

Aquarium Gravel River RockIf you have been looking for classic stone for your Aquariums, center table or even vase, this is the best you will find among hundreds of options available. These are lightly polished stones that are available in multiple natural colors. The package includes 18 pounds of large and small size river rock stones.

You can find a variety of natural colors such as brown, black, and whites. They resist fading are long-lasting. Make sure that you rinse the rocks thoroughly before using it for your aquariums.

These rocks are often accompanied by certain chemicals coated on them which may be harmful to other fish. So, it is advisable to rinse off all those chemicals. You will see that the polish remains intact despite rinsing the chemicals off since these are high-quality stones.

These rocks can be nicely placed on the base of the aquarium and look beautiful. It is perfect for both small as well as large fish tanks. The number of stones that arrives in your package is way too much to be used entirely for a small tank like below 5 gallons. So, you can use the remaining for your vase, candle stand, ponds, etc. it will keep your aquarium clean at all times, and there wouldn’t be any problem of water displacement.

The price range is also very average and affordable. Most importantly, these rocks are long-lasting and wouldn’t worsen over time, so it is worth every penny.


  • Affordable
  • Available in a variety of colors
  • Used for multiple purposes
  • Keeps the tank clean
  • Suitable for both small and large tanks


  • Needs rinsing before use
  • Should be kept away from children

8. Pisces 17 lb Seiryu Rock

Pisces 17 lb Seiryu RockThese natural-looking rocks made by Pisces is yet another one of the best aquarium rocks that you have come across. Not only they are unique in their structure, but also look incredibly beautiful inside a tank.

If you worry too much for your fish’s safety, these rocks are the ones for you. They are very safe for your fish and completely non-toxic. These rocks have been crafted beautifully making sure it enhances the beauty of your aquarium.

Eventually, it does affect the pH balance of the water due to the chemicals it has in its composition. But overall, it isn’t a lot which means this factor can be ignored.

The Seiryu rocks are available in several different sizes and shapes. The package that you will receive weighs about 17 pounds. One thing to notice is the large size of these rocks. You receive about 4-5 pieces in each package, and you can carefully place it in your tank depending on the size of the aquarium you have. Always rinse the rocks before using it to remove any harmful chemicals coated over it.

It may be a bit difficult to adjust these rocks in a small tank so make sure you buy it only if you have a tank above 20-gallon capacity. These rocks look incredibly stunning and perfect when placed correctly in the tanks. Also, the money isn’t a lot to pay, so if you have this kind of a budget, this could be the best option.


  • Affordable and durable
  • Visually natural and stunning
  • Keeps the tank and fish safe
  • Perfect for large tanks
  • Available in different sizes and shapes


  • Not ideal for small tank
  • Needs proper rinsing before use

9. Vorcool Aquarium Sea Rock Cave

Vorcool Aquarium Sea Rock CaveThis is probably one of the best rocks for a freshwater aquarium that I have ever come across. It looks very realistic and has a cave-like structure.

Moreover, this Sea rock cave has a spacious place inside it, which serves as a hiding and resting place for all the aquarium dwellers.

You will be thrilled to know that the rock has a perfect size and can be used for both small as well as large-sized tanks. Not just this, the resting space inside the cave is big enough to accommodate a normal-sized goldfish.

The edges are well polished, and there aren’t any sharp edges. But to be cautious, make sure you have sand down the rock to avoid any sharp edges.

This rock is made of resin material and is Irony grey in color. Well, once you receive the package, you can see a hint of greenish hue as well that gives the rock a more natural glow to it. Make sure you clean it carefully since mostly every rock is coated with some chemicals to preserve it. You wouldn’t want to harm the fish with these chemicals, so either rinse it or wipe to clean.

This is also the cheapest option there is with such an amazing rock for your aquarium. If at all you do not find anything that fits your match, I am pretty sure this is the perfect go-to option. Not only is it cheap, but also very safe and non- toxic for your tank and fish dwelling inside.


  • Cheap and Affordable
  • Lightweight
  • Ideal for small and big tanks
  • Perfect for big fish like Goldfish
  • Safe to use and non-toxic


  • Little sharp edges
  • Coated with chemicals

10. Royal Imports 5lb Large Decorative Polished Gravel River Pebbles

Royal Imports 5lb Large Decorative Polished Gravel River PebblesThese gravel river pebbles by Royal Imports are high-quality natural stones perfect for freshwater aquariums, ponds, home decor, etc. The package that you will receive weighs about 5 pounds and contains all different varieties of rocks.

These rocks come in two different color combinations that are natural and light. The natural colors include brown, black, white, and come in other color patterns.

They are non-toxic and completely eco-friendly and provides a natural attribute that makes them last longer than the mulch.

The most effective use of these rocks is for decorative purposes such as flower arrangements, vase fillers, walkways, water features, exposed aggregate flooring or walls, swimming pool areas, and many other areas.

Such rocks have no sharp edges, which is why it is safe to walk on without hurting your feet. These river rocks have a unique shape due to which they look very attractive and helps in proper drainage and erosion control. The package includes a netted bag that contains approx 160 pieces of well-polished stones.

It is advisable to wash these stones or rinse them properly in warm water. It will ensure the removal of any chemicals, bacteria, fungi, or parasites that the surface may have caught over time.

Apart from being incredibly cheap and affordable, it resists fading no matter how much time it is underwater. You cannot deny the fact that this is the best rocks for Freshwater Aquarium.

Also, you can use it for your small tanks and even larger ones. These rocks have an approx size of 2.00″ to 0.75″. Also, precaution needs to be taken while keeping it near any children since these pebbles are very small and may harm any child that swallows it.


  • Cheap and Affordable
  • Comes in a variety of colors
  • 100% natural and eco-friendly
  • Non-toxic and resists fading
  • Perfect for decoration in multiple places


  • Needs thorough rinsing
  • Smaller than anticipated

11. SevenSeaSupply 10 lbs Ohko Dragon Stone Rock

SevenSeaSupply 10 lbs Ohko Dragon Stone RockThe Japnese Ohko stone, also known as Dragon Stone, is lightweight and exotic used for decorating aquariums, terrariums, and bonsai tree displays. They are very lightweight and tan in coloration.

These Dragon Stones are mostly found in tidal waves that cause constant erosion due to which the stones feature many caves and holes with time.

The package contains well packed and sealed rocks protecting it from any harm. You are most likely to receive several different shapes with various sizes. So it may be possible that it isn’t very much suitable for small tanks.

As seen, these rocks are clay-based entirely, it wouldn’t affect the composition or the pH of the water under any circumstances. Well, it is highly recommended to wash or rinse the rocks properly before putting it inside the tank. There are chances of layers of residual dust coating over the rocks which may not be good for the tank dwellers.

It could be a little costly as compared to other options available. But if you feel this design of the rocks which is perfectly natural suits you, then you should go for it. Also, this tank is perfect for medium and large aquariums.


  • Lightweight and tan-colored
  • Perfect for medium and large aquariums
  • Used for decorating aquariums, and other purposes
  • Various sizes and shapes available
  • Completely Natural


  • Expensive
  • Needs proper washing to remove residual dust

12. Fluval Polished Ivory Stone

Fluval Polished Ivory StoneThese finely polished earth stones are one of the most beautiful stones you will ever find among the list as mentioned. They are egg white-colored small rocks that look visually stunning, and your fish would love it.

They are smooth and shiny premium quality stones produced using time-honored rock tumbling methods. This is a time-consuming method which involves immense hard work giving such quality results.

The package contains various sizes of these rocks. You can mix and match other decorative items to make your tank look more stunning.

If you have small fish like Betta, they would love the entire setup since they cannot snag their fins on them. They are entirely natural stones, and will not affect the pH balance of the water, so it is safe to use. Stones are generally chemical free and hence non-toxic.

But to make sure you have taken enough precautions, wash these rocks thoroughly so that if at all any chemical coating persists due to packaging, it is removed. Any type of chemical can be harmful to the fish.

Overall, it is a great product and fantastic addition to the list for you to choose from. The cost is also not too much and affordable. So, if the features are good enough for you, then you can consider buying it.


  • Affordable and cheap
  • Suitable for any size of the tank
  • Great for Betta fish
  • Perfectly polished and shiny
  • Keeps the water balanced


  • Needs well cleansing before use

13. Galashield River Rocks Polished Pebbles

Galashield River Rocks Polished PebblesThe Galashield River rocks are one of a kind pebbles available in various colors and sizes. The package is available in either 2 pounds or 5 pounds weight. The sizes available are 1-2, 2-3, and 3-5 cm, depending on the weight of the product you have chosen.

These natural stones are also available in various shapes and colors such as white, brown, gray, and white. Not only this, you can find multiple patterns on these stones. They are well polished and have a smooth finish with no sharp edges.

Most important, they are used for decoration in areas such as aquariums, terrariums, ponds, vases, swimming areas, home decor, etc. All these places tend to look much beautiful and shiny with the addition of these rocks as decoration.

All of the stones are highly durable and strong. No harm would come to them as the tie passes that is it resists fading. Since they are natural stones, they are most likely to prevent any change in pH balance or composition of water under any circumstances. The 2 pounds bag contains an approx 35 stones or even more. It has a mixture of all the sizes of stones, as mentioned.

The size of your freshwater aquarium will not be an issue since it is perfect for any size of the tank such as small, medium, or large. This is probably the most affordable and low-cost stones available in the market with such high quality.


  • Cheap and affordable
  • Multiple shapes, sizes, and colors available
  • Perfect for small, medium, and large tanks
  • Durable and Strong
  • Natural stones do not disrupt the balance of water


  • Not polished perfectly
  • Larger than anticipated

14. Cnz Polished Gravel

Cnz Polished GravelThe CNZ Polished Gravel are high-quality natural stones brought by CNZ and one of the best rock for freshwater aquarium. The package contains 5 pounds of natural black colored rocks with size 1″-1.5″ perfectly suitable for freshwater aquariums.

Not only this, if you have been looking for a decorative piece of such as this, it goes perfectly well for your home decor, vase, ponds, swimming area, landscaping, etc.

These rocks are eco-friendly and non-toxic. They provide a proper base or surface for the growth of beneficial bacteria. These good bacteria are favorable for the water composition and keep the tank free from any harmful bacteria.

Such bacteria feed on fish waste and keeps the aquarium clean. Just like natural plants that provide growth of these healthy bacteria, these rocks tend to serve the same purpose.

The 5 pounds of rocks aren’t a lot when it comes to the number of rocks in the package. So, to fill up the base of the tank with these rocks, you need to get multiple units, especially if you have a big tank. Though the cost of each package is very low, having a big tank can make the overall cost a bit high. If you really like them, then money should not be an issue. These rocks are very durable and strong and look stunning.

You can make out that they have been handpicked and not polished after that. So, this could be a disadvantage that they are not shiny over the surface. Make sure to clean them before use; you may not know what chemicals or dirt they might have acquired. So, it is safer to clean them before use.


  • Affordable and cheap
  • Used for decorating multiple places
  • Strong and durable
  • Eco-friendly and non- toxic
  • Provides growth of good bacteria to keep the tank clean


  • Not polished and has no shine
  • Needs cleansing before use

15. Lifegard Aquatics 25G-Smoky Mountain Stone

Lifegard Aquatics 25G-Smoky Mountain StoneThis smoky mountain stone is one of the premium quality rocks that you will find among all. The kit includes one large, two medium, and six small rocks perfect for the 25-gallon capacity tank.

You can also go for the 10-gallon kit that includes two medium and three small rocks. Well, anything less than that would not be an ideal size for these rocks to be put in.

These rocks introduced by the Lifegard Aquatics are an incredible looking unique stones that create a beautiful ecosystem for your aquarium. These rocks are completely natural that has the shape of a mountain.

You can easily set up the tank using these rocks set over the base of sand or other material whichever suits you better. But do keep in mind to have a proper base so that the rocks can have suitable support to sink in.

You would love the entire set up of the tank and is a perfect fit for big fish like Goldfish. The best part of you can easily use the larger kit for tanks higher than 25-gallon capacity. Since these rocks are way too big, they would fit in perfectly for much larger tanks and equally complement it. The price of this kit is surely higher than one would ask for, but if you like the structure and feature, you can go for it.


  • Available in multiple sizes
  • Natural mountains stone
  • Unique style and color
  • Perfect for large tanks
  • Visually stunning


  • Expensive
  • Not suitable for very small tanks

Frequently Asked Questions

1. Why Do We Need Rocks For Freshwater Aquarium?

Several possible reasons ensure that you must have some rocks in your aquarium, no matter how small or large-sized it is. It will not only make your aquarium look exquisite but also keep it safe and healthy in many ways.

1. There are a variety of rocks available over the web for you to buy, with various sizes, shapes, and colors. They serve as an amazing decorative material for your freshwater aquariums, ponds, home decor, swimming areas, habitats, etc.

2. The water in the tank needs the growth of good bacteria through natural processes, which help to clean the tank naturally. Some kinds of rocks produce bacteria similar to what some plants provide.

3. Several fishes feed on algae and other organisms for food. This is the reason that rocks are needed for your aquarium if you have such fish. The rocks, over time, get coated with algae which are further useful for other fish.

4. If you are looking for a resting or hiding place for your fish, then rocks are the most beneficial in such cases. Many rocks or stones have holes in them that provide spacious areas for fish to rest.

2. What Rocks Are Safe To Use For An Aquarium?

It is always recommended to buy rocks from someplace than just picking by yourself from any sea bed. The reason being, you may have no idea about the type of rock that would be in the first place. Also, there are various methods to choose a rock depending according to your aquarium ecosystem and the fish in it.

There are several rocks which may be coated with certain harmful chemicals or other microorganisms that could be deemed hazardous for your aquarium dwellers. The rocks that we have listed in the list above are all very safe and non-toxic.

To select the safest rock, make sure they are naturally made, and does not have any coating on it. For example, Slate, Quartz, Granite, Pumice, Onyx, Lava rock, Petrified Wood, etc. are known to be the safest rocks that you can buy without a second thought.

3. How To Clean The Rocks Before Use?

The rocks that you receive after purchasing online aren’t 100% ready to be used instantly. You need to wash them to remove any residual dust, chemicals, algae, and other organisms. If you aren’t planning to wash them, then these rocks can pose a threat to the health of the fish and the water overall.

Mostly all the kinds of rocks need thorough rinsing underwater for a while. Some may contain layers of residual dust that can make the tank water cloudy and unfit. So it may take a while to clean it up. You can also keep the rocks in boiling water (do not boil the rocks along with the water). All the chemicals will come off, and you will get instant shining stones.

Also, not every rock needs boiling water to clean up, such as those made from clay. So, rinse it gently under normal tap water. Once you are done with this, you can use it for decoration in your aquariums or any other place.

Many rocks have holes in them which serve as a resting place for fish. It may be possible that they get dirtier over time, so make sure to clean them at regular intervals for a healthy ecosystem for fish.

4. How To Test Rocks For An Aquarium?

If you have been planning to collect the rocks on your own, that is not a good idea. Many rocks you will collect may or may not contain calcium. This calcium may change the pH balance of water or its entire composition, making it unfit for fish.

To test rocks if they are safe or not for your aquarium, follow these steps:

1. Wash the rocks thoroughly underwater. Avoid rocks such as limestone, shells, marbles, geodes, and dolomite.

2. Now, drop small drops of vinegar over the rocks and wait for a few minutes. If the rocks start to foam or fizzes at any point in time, then it contains calcium which can be harmful for direct use in the aquarium.

3. Another way to test the rocks would be by checking the pH and hardness of water when rocks are placed in it. Just take a small amount of aquarium water in a bucket and put the rocks in it. Check the initial pH and hardness. Wait for a few days and check again. If the levels have changed, it is likely to cause problems to your entire tank as well.

5. Can I Use Live Rock In Freshwater Aquariums?

Live rocks generally produce an array of bacteria, algae, and other organisms that acts as a natural filter to keep the water clean and healthy. But such rocks are risky to use if you do not have much idea about which ecosystem would be perfect for them. Not every fish can cope up with the increased level of hardness or change of pH in the water.

Yes, you can use live rocks. The advantages of these rocks are:

1. The bacteria generated by these rocks would ensure that to convert the excess ammonia in the water and convert them into nitrite than less toxic nitrate. This keeps the water healthy and stable.

2. As you know, there is a disadvantage caused by the increase in the hardness level of water. But there are some fish then look for such a condition to thrive. If you already have such fish, then you are good to go.

3. Also, live rocks tend to produce algae in the water. These serve as food to feed certain species of fish. In turn, they help to keep the tank clean, and no extra food is needed for them.

6. Which Rocks Are Unsafe For Freshwater Aquariums?

It is generally recommended to avoid rocks that are high in calcium or the ones which would increase the pH of the water. Well, live rocks are the best example in this case. They are high in calcium which means an increase in the hardness of the water. But people are still buying it since many fish love the hardness of water and can survive better.

So, rocks such as Limestones, marble, and dolomite are some of the rocks that you should avoid while choosing since they have high calcium content and makes the tank unfit for fish to dwell or survive. Moreover, shells and corals are also known to be unfit for freshwater aquariums. But creatures like African cichlids love the increased pH and hardness of the water.

7. Why Are Pebbles Or Gravels Needed For Freshwater Aquariums?

The small pebbles and gravel not only give a stunning visual for the humans but also acts as a base of the tank to hold live plants and keeps the tank clean naturally. Well, this isn’t an absolute necessity, but it is recommended for various purposes.

The reason why gravel is necessary are:

1. They act as a natural biological filter for the tank. These rocks create beneficial bacteria to eliminate the waste produced by the fish, leftover food materials, and other debris. If the tank is left without any base, then it would disbalance the composition of water.

2. Gravel act as the home for live plants. These act as a substrate for plants and create a good base for the roots to settle correctly.

3. Lastly, these rocks hide any waste product or any debris that settles at the bottom and makes the tank look appealing at all times.

Best Rocks for Freshwater Aquariums: What’s Your Pick?

So, we have listed down everything that you need to know about rocks and all the conditions associated with them. Hopefully, now you will be able to pick the Best rocks for freshwater aquarium from the curated list which we have mentioned above.

The best among them would be the various kinds of pebble stones that are mentioned in the list. They are affordable and cheap and serves the best purpose overall. Apart from this, you can go for medium-range beautiful rocks that have been picked up from the sea beds and have various sizes and shapes. If you have big tanks, you can pick out the single rock with a cave-like structure that is perfect for your fish that would love to rest and hide in those spaces.

Overall, make sure whichever you chose is the best choice based on your tank size, fish, and the ecosystem you want to set for the fish. The better the ecosystem is, the better the fish will dwell in for longer.

Also if you are still unclear about the options which you would select, you can always contact us with the type of tank, fish, and ecosystem you have created, and maybe we can help you pick out the best aquarium rock.