The Best Rocks for Freshwater Aquarium to Decorate Your Tank

best rocks for freshwater aquarium

Rocks for freshwater tanks should be inert. When you say inert, this conveys that the rocks should have no effect on the hardness or pH of your fish aquarium water. It is essential to note that freshwater terrains are regarded as soft water; as a result, putting the wrong types of rocks to your aquarium would just affect your water to be hard so your tank occupants will find it uncomfortable to dwell in.

To boot, an African Cichlids plus many other hard water originating freshwater fish are exclusions to where you could utilize calcareous rocks that do not contain salt. Basically, calcareous rocks contain calcium and are known to bring about pH and are also the cause of boosting hardness in tank water. It is usually beneficial to add clean wood that aids soften the water if you opt for a softer freshwater.

Aquarium rocks are a vital part of creating any tank’s aesthetic. But I’ve often seen people overwhelmed by the number of aquarium rock decor options. So here’s a look at some impactful factors to help make this process much less stressful.

  • Color: Stones for aquarium tanks are available in various colors. Generally, freshwater tank owners prefer using colorful fish tank rocks like red or pink. These options provide a lively aesthetic while being beneficial for the fish.
  • Budget: Crafting a budget based on your needs is invaluable. After all, this marketplace offers a wide range of price tags. So buyers must consider what they value to ensure they only spend what is necessary.
    If you’re buying rocks to layer the tank’s bottom, make sure there’s enough to cover a depth of at least 2 inches. For those with large tanks, this might mean more rocks are required, which calls for a bigger budget.
  • Rock Size: Freshwater aquarium owners must choose a meshable rock size. These rocks have to fit into your tank without overcrowding it. It creates an uncomfortable environment for plants or fish if they don’t.

Those getting rocks with crevices for fish to hide in must also ensure the hole is large enough that the fish can comfortably dwell inside.

If you are currently in search of the best rocks for freshwater aquarium, take in mind that some of the inert rocks that are certainly risk-free options and could absolutely look appealing in your freshwater aquarium consist of plastic rocks, basalt rock, lava rocks, quartz, slate or shale.

Best Overall

Royal Imports 5lb Large Decorative Polished Gravel River Pebbles Rock

Royal Imports Pebbles Rocks

✅ Non-toxic and environment-friendly
✅ Ideal for home decor
✅ Excellent shapes


Premium Choice

WAYBER Aquarium Rocks

✅ Promotes better tank quality
✅ Safe, non-toxic natural construction
✅ Usable in multiple applications


Editor’s Choice


Natural Slate Stone

✅ Exceptional shape and size
✅ Naturally hold heat
✅ Attractive home décor


5 Best Freshwater Aquarium Rock Reviews

1. Royal Imports Pebbles Rocks

Royal Imports 5lb Large Decorative Polished Gravel River Pebbles Rock

If you would like to shop for safe and natural rocks for fish tank, then this Royal Imports pebbles rocks will definitely be a great addition to your tank. This won’t only help make your aquarium look more attractive, but your fish and other invertebrates will surely love them too.

The common applications for this type of pebble rocks are for decorative concrete topping, flowerbeds, walkway paving, and groundcover. These are ideal pebble rocks that are deemed as an economical and permanent option to yearly wood composting.

These rocks are highly recommended for air plants too. They are comparably uniform in texture and size and they also come with an adequate variation which is specially intended to provide more uniqueness and appeal. These are softly polished and because of that, the colors stay real without much luster. The undertones are great to behold.

The colors of these pebbles are natural and mainly consist of diverse shades of black, white and brown rocks. They are easy on the feet since they do not have sharp edges. They come in a wonderful combination or medium-sized and large non-toxic stones.

What is more, just like sandstone in aquariums, they could serve as a very lovely embellishment to tanks, garden, flower arrangement, bird feeders, and many other interiors and exterior décor purposes. The package contains sufficient natural stones for you to use.

Please be guided that you need to rinse them properly prior to adding them to where you intend them to be. This must be carefully done if you plan to add them to your aquarium.

  • Non-toxic and environment-friendly river rocks
  • Ideal for home decor and an artistic interior/exterior design
  • Excellent shapes that provide good drainage
  • Practical alternative to yearly wood mulching
  • Durable and does not deteriorate instantly
  • Have the tendency of forming molds
  • Slightly lusterless
Right to it, the reason why these rocks are a must-buy is that they come in many different uses. They are not merely for beautifying your potted plants, lawn or garden but these are also perfect alternatives for your tank. For a fact, these are very well-known accents to tanks, terrariums, ponds as well as water gardens.

2. WAYBER Decorative Aquarium Rocks

The WAYBER Decorative Aquarium Rocks will be a welcomed addition to any freshwater aquarium. Their non-toxic natural composition makes them one of the more adaptable and safer rocks for aquascaping or freshwater tanks. I found them ideally suited for what I wanted in these products.

For instance, these rocks allow water to flow through them without issue. This promotes better water quality inside the tank rather than polluting it like other substrates. Sadly, in my previous enclosure, I learned the hard way when using lace rock structures or slate rocks for aquariums.

I was also impressed by these rocks’ low maintenance levels. After all, I’m a rather busy person, so anything to limit these tasks as much as possible is a must. This option certainly meets my needs in this regard.

Similarly, these rocks had no problems meeting my tank’s aesthetic needs. WAYBER allows each buyer to choose from 8 color options to ensure these rocks are perfect. I chose the black over the dark blue sea glass or clear/white rocks.

But I could see how all eight choices could make an aquarium owner happy, especially considering the diversity. After all, these rocks are adaptable to almost any situation. They would be perfect for home decor, party decor, or planted tanks.

I do have a gripe with these rocks having misleading ad pictures. It has caused a few customers to be fooled by the size and quantity of this option. It also doesn’t help that this option is among our most costly choices.

  • Safe, non-toxic natural construction
  • Promotes better tank quality by allowing water to flow through
  • Requires little to no maintenance or care
  • Adaptable to various aesthetics with eight color options
  • Usable in multiple applications
  • Pictures are a bit misleading about size/quantity
  • A higher-priced option for the provided amount

In any case, I don’t find myself worrying too much about these concerns. The description itself is clear about the amount. Plus, I’m more than okay with paying extra for quality; these rocks certainly meet those qualifications.

3. Natural Slate Stone


If you plan to shop for cool fish tank decoration ideas, the natural slate stone is a great pick. This works superbly in embellishing your home, as a ground cover for indoor plants and when designing vases and bowls that are displayed in your dwelling place.

They actually come in multiple uses and are a famous choice when crafting steps, caverns, archways, doll houses, model railways and the like. Since it comes in many different uses and is not only meant for aquariums, then it is safe to say that it is a practical choice to consider.

Furthermore, they look amazing with bonsai in your garden. They can provide wargaming miniatures a more realistic and natural backdrop. They are natural grey slates which are generally darker when drenched. Meanwhile, if you prefer to darken them permanently, you may consider using a clear finish or a sealant to do so.

It is certainly nice to know that they come in a variety of shapes and sizes. The larger ones can be used to construct the cave and for some backdrop pieces, on the other hand, the smaller ones are good to utilize around the tiny hill to ward off the emergence of landslides.

Basically, it is easier to glue them together so you can instantly craft a hiding hub for your freshwater tank. But, most of the pieces were quite thin. You need to gently rinse them prior to using them.

  • Ideal for constructing ground cover, fairy gardens, and walkways
  • Superb for vivariums, terrariums and aquascaping tanks
  • Exceptional shape and size for rock painting
  • Can naturally hold heat for reptiles
  • Attractive home décor in vases and bowls
  • Come with mini broken bits that chip off the ends
  • Not ideal for larger tanks or larger aquascape project
Overall, these rocks are precisely what you need. If you keep reptiles, these are good choices that differ in size and shape; however, there is a sufficient amount of larger-sized ones as well, not so round, gray and flat. As you can see, these are perfect for any tank, garden or terrarium. These are a good option to spend a dime with.

4. VORCOOL Aquarium Sea Rock


This VORCOOL Aquarium Sea Rock Cave Ornament is one of the best rocks for aquariums because it looks somewhat realistic in the tank and comes with a fine size of three by up to ten-gallon tanks. With that, you can be guaranteed to give your tank occupants a great spot to hide and get out of the light whenever they prefer to.

If you are looking after a Betta, then make sure to sand down this rock’s edges to avoid any issue. The holes are adequately-sized so your Betta could glide in and out without the need to accidentally hit the sharp edges.

Since this rock comes with sharp edges, it could be slightly tough to tidy up unless you have a tiny critter that consumes algae. Without a doubt, your marine friends will love it and that alone will make you elated with your purchase.

Nonetheless, once you are already opening the package, you will smell something nasty; somewhat a chemical-like smell that may irk you. This is the reason why it a must to clean it well before putting in your tank as it may also disturb your freshwater pets.

Also, you need to fix the sharp edges by means of gently sanding them down so that your tank occupants will remain safe.

  • Ideal for Cory fish and bottom inhabitants
  • Provide a nice dark area for fish to chill in
  • Very attractive aquarium décor
  • Give the tank a more natural look
  • Can provide the necessary air to African dwarf frogs
  • Smell like chemical at first
  • Come with sharp edges

All in all, VORCOOL Aquarium Sea Rock Cave Ornament is worth every single penny you pay for it. It is the ideal size decoration for any aquarium. Over and above, with its real looking moss, it seriously comes across as authentic and not a mere resin. This simply implies that you won’t waste your money on unreliable fake aquarium rocks.

The only drawbacks are the sharp edges. Fortunately, these won’t be a big issue for you to deal with provided you gently sand them down and tidy them up accordingly.

5. American Fireglass Black Lava Rock


Are you presently hunting for a premium quality lava rock in aquarium? Then, American Fireglass lava rock will work wonders for you!

We all want to invest in products that are premium quality, low maintenance, economical and can stand the test of time. By happy chance, these rocks come in a variety of sizes and come with a porous surface. They are especially ideal for fire pits, fire bowls, and other outdoor or indoor fireplaces.

It is interesting to note that you may also consider utilizing these fire pit rocks on as filler or base for other ornaments or if you prefer they can be used on their own.

These rocks work great at improving your sanctuary. As a matter of fact, black lava rocks are less expensive ways to provide your fire feature a classy, lush and fascinating look. Without question, naturally emerging fire pit rocks appear peculiar and have a magnificent burning effect.

Nevertheless, these rocks require thorough cleaning prior to using them in an aquarium. See to it to gingerly sift through it and do not cheat on this labor-intensive cleaning procedure because these lava rocks are not particularly meant for tanks.

They will only be safe and good to use in tanks if properly cleaned prior to adding them to the tank.

  • Certified all-natural lava rocks
  • Ideal for indoor or outdoor use
  • Long-lasting and great value for the money
  • Easy to maintain
  • Aid in retaining moisture to plants
  • Tendency of algae growth
  • Slightly dusty when not properly washed

It is not surprising why these rocks are one of the topnotch options. In reality, many consumers adore their all-natural feature. This means that they are formed as volcanic magma that rises to the surface and afterward cools and dispenses gases.

They can combat the most extreme temperatures without easily crumbling and being damaged and these medium-sized rocks are certified stunning addition to your fire feature.

Aside from this, these are actually good-looking tank gravel that you can purchase for your tank inhabitants. Aren’t these enough reasons why they are great items to invest in? As you can see, these are multi-purpose making them an even more cost-effective option that you can spend in.

Outdated Products

Nature’s Ocean Coral Base Rocks (Outdated)


Undoubtedly, it is not a piece of cake to shop for big rocks for aquarium since there is a significant number of an option to select from. If you would like to avail something that comes in superb specifications, then you may check out Nature’s Ocean 12-Inch Coral Base Rocks for Aquarium.option

This product is capable of instantly adapting to the live environment and does not do anything negative to the cycle of your aquarium. It can serve as a naturally porous biological filter, does a very vital job in aquascaping and it is certified free of Biofilm.

On the other hand, it is worth mentioning that it is indispensable to soak it in deep water accordingly so as to ward off leeching.

This type of rock comes with naturally molded crevices and holes that allow for some distinctive and very engrossing shapes. In the same way, it can be easily piled up when crafting a base for flourishing live coral or when you consider utilizing it to the current coral-based environment.

  • Appealing tank decorations
  • Known for conserving natural reefs
  • Ideal for growing live corals, culturing live rocks and coral farming
  • Does not have a huge effect on the cycling of the tank
  • Biofilm-free and good for aquascaping
  • May require deep cleaning prior use
  • Slightly expensive

In a nutshell, this product is a cost-effective alternative for having a porous feature in that it serves as an ideal ecosystem for denitrifying bacteria that develop in water – as you can see this efficiently aids in minimizing nitrates in the aquarium.

It is nice to know that this product does not solely focus on being a lovely embellishment in your tank but more especially it does serve very valuable purposes that benefit your tank inhabitants.

However, of course, you need to save more money as this is a bit pricey to invest in- this is quite normal though since you can no longer get good stuff for low cost these days!

Pisces Seiryu Rock (Outdated)


These rocks are highly recognized for being the best rocks for freshwater aquariums. They are hardscape types of stones that are specifically created by skillful designers to provide a more realistic presence that is ideal for Amano or Iwagumi kind of aquascaping.

You do not need to worry about the safety of your aquarium pets since these are all-natural stones that are non-toxic for shrimps and other plants, with minor changes to the chemistry of water. They are particularly utilized in creating a natural backdrop in your setup, bonsai garden, terrarium, conventional Japanese rock garden or biotope tank.

Besides, these are creatively selected and sculpted to appear like pint-sized rock formations that come with different shapes and sizes for a more distinctive look. They sink instantly which means they are quite easy to put in the tank without worrying about any drift problems.

What makes these stones a great pick is that it is effortless to immediately place them into an iwugami-style layout. So, that means you do not need to be a pro to make your aquascape something nice to behold and a perfect dwelling spot for your tank friends.

These Seiyu rocks are truly attractive, comes with nice grains and they do a very great job at stuffing plants and moss into. This is a great value for the money. You don’t need to search elsewhere if you are looking for gorgeous rocks for your aquascape project!

Likewise, they serve a very advantageous purpose of naturalizing the scenery in your tank. It is stunning to see mosses as they aid make the aquarium appear like an impeccable fish zen.

  • Reptile and aquarium safe
  • Fascinating rocks at a superb price
  • Come with premium quality and variety
  • Good embellishment for tanks and terrariums
  • Come with unique crevices, textures as well as shapes
  • Natural stones don’t look clean
  • Rocks are slightly heavy
All in all, these are certified great stones to purchase. They could serve as a fantastic centerpiece of your aquascape. These natural stones will work excellently when you decide to replace the decors in your tank. They can also provide your aquarium occupants a very cozy hiding hub. These are a great deal even for new aquascapers!

Worldwide Imports AWW0855 Atlantic Coral Rock (Outdated)


The rocks are considered one of the best aquarium rocks that you can purchase since they are easy to aquascape. They are porous and there is no need for you to utilize any putty or glue just to stick them together.

As compared to other reviews that say these rocks are unreal, if you’re going to look closely, you will observe that they actually come with some browning on them which simply implies that this is one quality of an authentic dry rock.

More than that, they come in plenty of large sizes which can be broken down to medium-sized chunks through the aid of a hammer or chisel. They are slightly dense too. As you can see, you can make use of all these rocks in order to create a more impressive island to long aquascapes on longer aquariums.

This is a great option to reduce the cost of such factors that make aquascaping quite costly. This is the exact definition of getting more for less and its quality is king.

And, it is worth noting that the rock looks stunning in the tank and a nice led light would really do a great job in popping them out. Since these are porous, it could provide beneficial bacteria that could grow well and become live rock when appropriately aged.

However, it looks messy at first. Please be guided that they may require a significant amount of time to clean them up. It may take a few days for the tank water to clean up specifically if you do not wash it off carefully.

  • Real dry rock from the Atlantic ocean
  • Premium quality
  • Great value for the money
  • Easy to pile and looks natural
  • Superb deal and variety of sizes
  • Rocks were jammed up with sand in all of their holes
  • Somewhat brittle
In sum, this purchase will make you delighted and you’ll be glad not to spend a dime for lesser weights on dry rocks. What is more, this rock’s outstanding variability can be one of the primary reasons for your purchase.

SevenSeaSupply Ohko Dragon Stone Rock (Outdated)


If you are a tank owner, you would surely agree that it can be daunting to keep a safe haven for your aquarium friends at times. In addition, it isn’t easy to make your aquarium look fascinating not only to your guests but more so to your freshwater friends.

Luckily, with the aid of fish tank river rocks, you can create a wonderful dwelling spot for your freshwater pets and at the same time keep them risk-free at all times.

SevenSeaSupply Ohko Dragon Stone Rock is the right choice for those searching for stunning rockwork. These rocks come with several caverns and holes that are mainly formed through erosion. Please be reminded that the stones require to be thoroughly washed prior to using them or adding them to your tank.

Once you opened the package, you will be pleasantly surprised at the condition of the rocks. They have large contrasts in terms of colors and are first-rate enough to craft a pleasant ambiance for your pets.

These rocks will definitely be adored by your freshwater pets since they have crannies and nooks to scavenge from and hide in. Keep in mind that if you do not thoroughly clean and rinse them with water, then the water in your tank will be cloudy as expected.

  • Can help add natural aesthetics to your terrarium or tank
  • Tan-colored and lightweight
  • Come with exotic-like specification
  • Packed with a good amount of premium quality rocks
  • Nice variety of sizes
  • Slightly brittle and easily broken during the wash
  • Look dusty upon received

In sum, what makes these rocks a good deal to go for is that they are an ideal mix of sizes and shapes that could complement your tank. As compared to other types of tank rocks, these are fairly lightweight and come with a stunning look.

On the other hand, it is crucial to be careful when cleaning them though, as they have the tendency to break easily if not properly taken care of. For sure, your tank occupants will love them as they could serve as a better hiding hub for them to use. They aren’t that expensive making them an even better deal to opt for!

Underwater Galleries Cichlid Stones (Outdated)


Underwater Galleries Cichlid Stones are nice to behold just like large river rocks for aquarium. They come in roomy interiors that are particularly intended for tank occupants to explore while at the same time providing shielded breeding niches for them.

This product is king because it is eco-friendly and won’t minimize or displace the amount of water in the tank. Moreover, it is formed with proper care and is certified hand-glazed to offer a more natural and attention-grabbing look of perfection.

These Cichlid stones come with a total of 6 big stones of 3 different versions and a total of 4 medium stones that also come in varying versions. When it comes to the colors, it is highly advised to avoid brushing them too hard when you clean them up. Clean them gently to retain the good color and texture.

The smaller stones have roughly a 1†openings- these are effortless to tidy and seem quite natural; be that as it may, these are not suggested for growing fish that might not be able to utilize the opening more easily. Indeed, these are lightweight. If you have bigger fish, it will be easier for them to block the opening or push them over.

These stones can serve as another hiding spot for your tank occupants so that they can have a place to hide and rest whenever they need to. The only problem with smaller versions is that since they are small, it becomes a bit tough for other fish to fit in. So, they commonly serve more like a decoration in the tank.

  • Does not displace a huge volume of water
  • A piece of cake to set up and move around
  • Comes in several holes and caves in tiny space
  • Made of high-quality ceramic
  • Environment-friendly and lightweight
  • Not as big as they appear
  • Surface of each cave is uneven

On the button, Underwater Galleries Cichlid Stones are smart purchase to consider just like limestone rocks for aquarium. These are well-crafted, and since they are made of ceramic; they are environment-friendly.

They come in a great package, and most importantly, they come with a variety of opening sizes for differently-sized cichlids. Undeniably, these will be a great addition to your tank!

Penn Plax Stone (Outdated)


Would you prefer to purchase something that looks like aquarium river rocks? Surely, we always wish for a tank rock that can add beauty to our aquarium and at the same time can serve as our most cherished fish’s hiding and resting spot. Luckily, Penn Plax Stone Replica Aquarium Decoration Realistic Granite Look can give you all that.

Since every rock is isolated from each other, you could instantly organize the stones as per your fish needs and aquarium size. Take note that the bigger stones come with a flat top for the purpose of piling up and more stability.

These stones are quite sturdy in that they are made of risk-free and solid resin. It also serves as a safe décor that can be used both in saltwater and freshwater tanks. The good news is that extra stones could be bought separately if you wish to construct bigger displays.

Many aquarium enthusiasts prefer this brand because its décor can provide visual interest for you and your tank inhabitants. Furthermore, the holes provide a hiding spot for them where they could immediately rest and conceal themselves from aggression and stress.

As you can observe, these granite stone replicas are definitely ideal for cichlid aquariums because this fish is territorial and it is imperative to construct their own space. Likewise, these tanks ornaments resemble what is found in a marine environment.

  • High-quality granite stone replicas
  • Can provide visual interests to both humans and tank occupants
  • Made of solid resin, durable and safe to utilize in tanks
  • Can serve as an ideal hiding and resting hub for fish
  • Can be utilized in both saltwater and freshwater aquariums
  • Bigger fish have the tendency to get stuck
  • Other stones in the package are slightly fragile
On the whole, Penn Plax Stone Replica Aquarium Decoration Realistic Granite Look is a great alternative for smooth aquarium rocks. Aside from their aesthetics, they could serve several useful purposes for both tank owners and their aquarium friends. The inhabitants in your tank will absolutely love them because these stones are capable of providing an ocean-like environment for them.

What To Look For When Buying Rocks For A Freshwater Aquarium


Selecting rocks for your tank should be based on appearances, cleanliness, safety and best value. As a result, when buying rocks online or at local fish stores, you may ponder on the following guides below so you can pick the most thriving and healthiest rocks for your aquarium:

  1. Search for appealing rocks that are colored red, pink and purple. The reason behind this is because such colors are deemed as matured and healthy coralline algae colors which your tank inhabitants will certainly adore.
  2. Do not opt for rocks that come with slimy texture and black algae for these are evident signs of dead entities that may contaminate the aquarium in the long run.
  3. Choose rocks that have crevices and holes in them for these will serve as hiding or resting hubs for your tank occupants. These could also act as great bacteria colonies. Check if the holes or crevices are big enough for fish to hide or dwell in.
  4. Carefully check the rocks for any signs of living creatures that may be dangerous to your fish as well. If the rock does not look good, then better leave it there.
  5. When looking for rock decors for your tank, smell them first. If they smell rotten or fishy, then this could mean they aren’t cured.
  6. Ask yourself how much you are willing to spend for rock decors to be added in your tank. Then, adjust your options based on that. But, be reminded not to compromise quality. Do not go for cheaper options if these cannot guarantee the valuable specifications that must be considered when investing in aquarium rock decors.
  7. Inspect if the sizes of the rocks you are eyeing to buy will fit well in your tank. Make sure that you do not over-decorate the aquarium as this will only cause congestion and discomfort inside the tank.

Other Important Factors To Consider


While you could set aside some bucks through adding local rocks to your tanks, if you pick the wrong type of rock, or you do not prepare them accordingly, then this could be dreadful. Note that some rocks have the capability to change the hardness of water, pH level, and this is particularly affirmed if you have naturally acidic water.

Also, other kinds or rocks might be contaminated with bad bacteria and other harmful organisms that could be fatal to your tank friends. Needless to say, common sense must always be applied specifically when putting rocks to your tank.

Evidently, it is not recommended to take rocks from a seriously populated spot. While it might be probable to get rid of all the toxins, the danger is simply too great for your tank pets. Additionally, any rocks that easily deteriorate would only create a problem in your tank- so; this must be avoided at all cost.

Most importantly, one of the most vital factors to check out is if the rock does not contain any metal. Take in mind that any rocks must be discreetly examined for veins of rust or metal prior to adding them in the tank. Be reminded that these kinds of rocks could be tremendously fatal to your tank occupants; therefore, stay away from them.

What is an aquarium rock?

An aquarium rock is commonly added to tanks to provide a natural-like environment to tank inhabitants. This is to help make the aquarium look attractive. Likewise, this helps in keeping the fish safe, healthy and happy.

How does it work?

Aquarium rocks serve as good bacteria colonies that are especially beneficial to fish. They can also serve as ideal hiding and resting places for tank occupants. Many of them can be sources of food for various fish and provide a natural looking environment for the fish to thrive.

What are the different types of aquarium rocks?

There are 3 primary categories of the kinds of rocks that could be utilized in aquariums- each of them has its own sub-category. This consists of igneous, sedimentary and metamorphic rocks.

  • Igneous rocks that can be utilized in tanks comprise of basalt, gabbro, and dolerite.


  • Sedimentary rocks consist of limestone, breccia, marl, conglomerate, sandstone, and shale.


  • Metamorphic rocks include dolomite, schist, marble, quartzite, gneiss, phyllite, slate and hornfels. Hinging on the biotype, take note that all of these rocks must be appropriate for aquariums.


Why do you need rocks for an aquarium?

If you own an aquarium, then you must specially consider adding some safe and appealing embellishments inside the tank in order for your fish not to feel dull and comfortless inside. Without question, tank decors can considerably aid avoid make your aquarium look empty and not a good hiding or resting spot for your tank occupants.

For sure, a lot of people would prefer to stare at an aquarium that has adorable and stunning woods and rocks inside. Indeed, rocks and other decors assist in providing an identical look of the natural ecosystem for the fish. Up until now, there are some factors to be mulled over prior to putting these decors to your tank which were discussed above.

Now, let us explore on the benefits of adding rocks to your tank!

  • Some fish feed themselves with algae from woods or rocks on their natural ecosystem. Hence, putting rocks in the aquarium will provide tank occupants additional instinctual activities and this is advantageous for them to have a natural and healthy form of diet.
  • Rocks can provide a wonderful spot for specific bacteria to nitrify and create their territory. Moreover, these are good bacteria that aid ward off toxic substances like nitrites and ammonia from tanks.
  • Nearly all aquarium enthusiasts prefer to keep fish in an environment that is identical to their natural ecosystem. This is not as valuable as in the past because lots of fish these days are generally bred in confinement. Nevertheless, it is still wonderful to see fish inside an aquarium that is a replica of their natural habitat.
  • Since most fish tend to conceal themselves from people and other tank inhabitants, rocks are effective spots for them to hide. Rocks also help fish feel more protected if these are utilized for living in caves. And, rocks can serve as a potential breeding place or laying eggs for your tank friends.
  • Rocks can be beneficial in setting certain water parameters that your tank accounts especially require.
  • The most typical advantage of adding rocks to your tank is for visual purposes. Surely, the aquarium will look more attractive if you incorporate eye-capturing rock designs.

Frequently Asked Questions


What rocks are not safe for aquariums?

Some newbie aquarium hobbyists assume every type of rock is usable in their tanks. Sadly, this belief couldn’t be further from the truth. After all, there are a few unsafe rocks for aquarium tanks, such as limestone, marble, and sandstone.

In short, any rocks with high sodium or salt content will be on the unsafe list. They can all harm your fish, especially in freshwater aquariums. In fact, these pebbles release harmful chemicals into your tank’s water, which can be very dangerous for aquatic life.

So users are much better off choosing rocks marketed especially for freshwater aquarium use.

The WAYBER Decorative Aquarium Rocks are great choices. They offer a wide selection of colorful freshwater aquarium rock options to satisfy every tank owner.

How many rocks can I put in my aquarium?

Most beginner aquarium owners become terrified when adding rocks to their tanks. It often stems from them worrying about adding too much weight, which could cause the glass to break. But there’s an easy way to avoid this issue from occurring.

It’s all about sticking to a straightforward guideline: never use more than double the weight of your tank’s capacity. So a person with a 20-gallon tank shouldn’t use more than 40 pounds of rock inside it.

Otherwise, it’ll cause serious issues when stacking to create an aquarium rockscape or rock formations. I wouldn’t recommend neglecting these guidelines with either hardscape or aquascape stone rocks.

Is it better to have sand or rocks in a fish tank?

Freshwater aquariums do much better with rocks (specifically gravel) than sand. They fit into the tanks more efficiently, allowing water to flow. As a result, rocks prevent bacteria and amoebas from creating a home for themselves inside.

So any freshwater tank owners would be best staying away from using sand. Instead, stick with the aquarium safe rocks list when crafting your tank’s aesthetic. Trust me; it’s not a decision you’ll regret.

I should also mention you shouldn’t just collect rocks for aquarium tanks. In other words, don’t use rocks found outside your home and expect them to be safe for your tank. It’s not a good idea and could expose your tank’s inhabitants to dangerous chemicals.

What are the most trusted aquarium rock brands?

There are limitless options when it comes to topnotch aquarium rock brands and a few of these include:

  • Underwater-Galleries-Ceramic-Cichlid
  • Penn Plax Stone Replica Aquarium Decoration
  • Vitality AF135 Aquarium Decorating Cave Ornament
  • MOSS Cichlid Stone Ceramic Aquarium Rock
  • Nature’s Ocean 12-Inch Coral Base Rocks
  • Natural Slate
  • VORCOOL Aquarium Sea Rock

Take note that these brands are trusted names because they provide safe and friendly rocks for tanks, they could ensure durability, can provide impressive décor to aquariums and high-quality products.

Where to find rocks for an aquarium?

Outdoor stones, as well as gravel, can be gathered yourself in great outdoors- from dry wash beds, beaches along the lakes and ocean, or from rivers and banks of streams.

Bear in mind that it is not suggested gathering stones from the lowermost part of active streams and rivers in wild and safeguarded ecosystems; this is primarily because taking away stones could dislocate or distract natural habitats that plant and fish life rely on.

What rocks are safe for aquariums?

The use of gravel, rocks, and stones in tanks is very prominent nowadays and you could purchase lots of diverse kinds from your local aquarium store or online shopping sites. However, you need to be insightful about the fact that not all rocks are appropriate to use for your tank.

There are specific rocks that may contain hazardous minerals or metals that may most likely change water chemistry or would leech into the water over time and this may lead to putting your tank inhabitants in danger or this could even lead to death.

Luckily, various aquarium shops are cognizant of this reason why they sell stones or rocks that are either natural or man-made and marked as “aquarium safe.â€

If you plan to buy stones or rock for your tank, the following types of rocks are safe to use for your aquarium:

  • Slate. This rock ages suitably in tanks but they come with sharp edges.
  • Quartz. This does not age well in tanks and can be sharp too.
  • Granite. This is bulky so it is important to position them appropriately. This is entirely safe to use for aquariums.
  • Lava rock. Make sure not to boil or roast this type or rock as they can easily break down. This actually contains chelated iron that is also ideal fertilizer to plants.
  • Onyx. This comes with natural dark gray in color and aids in enhancing the appearance of any tank.
  • Petrified wood. Before adding this to your tank, it matters to utilize the acid test first.
  • Pumice. This is actually glass and not actual stone. It might float in the water because it is quite porous. See to it not to boil or roast it.

How to clean rocks for a fish tank?

It is very important to regularly clean your tank to ensure that you provide a clean and safe environment for your tank friends. If you have stones and rocks in your aquarium, it is a must for you to clean them thoroughly as well.

Here are some guides for you to check out when cleaning the rocks or stones in your tank:

  • Decorative Rocks

Use algae scrubber or scraper to clean decorative rocks. This must be done every week during the time you need to change the water. You only need to gently brush the external part of the decorative rocks. Do not use tap water in swishing them for this may exterminate good bacteria. Rinse them in dirty water that you discharge when changing the water.

  • Live Rocks

These rocks do not need to be tidied regularly except that there is a serious concern in the aquarium and you do not have any other option. Rather than scrubbing them to get rid of scum or algae, it is better to create a habitat in the aquarium where rocks could obtain a biological and natural form of cleaning.

This simply implies adequate lighting, proper filtration, fish that consume algae and consistent pH levels. When cleaning live rocks, take them out from the aquarium and gently brush them with the aid of a soft brush; afterward, immerse them in salt water for about 2-3 days.

Make sure to ventilate the water with the help of air stone. Then, wash off the rocks in saltwater and put them back in the aquarium.

Where to buy?

Rocks for freshwater tanks can be purchased in different ways and from diverse sources and some of these consist of the following:

  • Garden nurseries or garden centers
  • Landscape firms that might sell sleek river rocks and other aggregates in a wholesale mode
  • Home improvement centers that have gardening departments in them
  • Various and trusted online shopping sites like eBay, Amazon and the like.

As you know, all of these sources can virtually provide you with less costly and attractive gravel and rocks. Take into account that you have to be careful in making your selections. It is advised to make it habit to test your gravel or rocks prior to utilizing them in a tank.


While it is true that adding stones or rocks to a tank is rapidly becoming a very renowned trend at present, still, it is better to administer a little research prior to making the final purchase. Make it a point that your rocks are aquarium-friendly and safe for fish. If you have problems with choosing what types of rocks to pick or you find it hard to identify them, you can consult your local aquarist for some assistance.

Laid on the line, it is seriously important to clean the rock carefully prior to adding them in the aquarium. Keep in mind that while decorating your tank with various plants and rocks significantly help make the tank look more attractive, some of these may only disturb or put them in danger; hence, you’ve got to ensure that what you add in the tank won’t make your tank inhabitants unhealthy and unhappy.

Hope the best rocks for freshwater aquarium reviews aforesaid are of great help to you!