A freshwater fish tank does not look right if it is bare. Aside from substrate, a freshwater aquarium will also need rocks so it will look natural plus they can provide your fish with a place where they can take shelter. However, you need to invest in the best rocks for a freshwater aquarium, instead of just picking rocks you see on the side of the road.
Aquarium rocks come in all shapes, sizes, and colors. Although they are typically used to add aesthetics, they also have some utilitarian purposes. As mentioned earlier, they can serve as shelter for small fish, especially for the fry. Also, they can make the tank feel more natural for the inhabitants.
If you are setting up a new tank, aside from the basics (filters, lights, etc.), you also need to think about the decorations. A good-looking tank will make you more invested in taking care of it. To help you get started at decking out your aquarium, here is a quick buying guide for the best rocks that you can add to your freshwater aquarium.
Best Rocks for Freshwater Aquarium Reviews
1. QIAONIUNIU Colorful Pebbles Stones Rocks
You will be getting a package that contains roughly 100 pieces of resin aquascaping rocks freshwater. These pebbles do not need any batteries or electricity to glow. You just have to expose them to sunlight or the LED lamp of the aquarium for a bit and they will “charge up” with light and glow when it gets dark.
Depending on how long the pebbles have been sitting under a light, they can glow brightly for a couple of hours. Don’t worry about these rocks making the water in the aquarium warm as they only emit light and not even a tiny bit of heat. Your fish will still be perfectly fine even if these rocks look radioactive.
Speaking of your fish’s safety, you don’t need to worry about toxic chemicals leaching into the water, as there will be none. These pebbles are made of natural resin, and the additives that make them glow are also non-toxic. I have had these pebbles in a small goldfish tank for a couple of months now, and my fish are still as happy as ever.
Aside from making the aquarium look pretty and fun, the glow-in-the-dark pebbles also serve as a sort of night light for your little tyke’s room. However, that does not mean these are solely for kids. If you like bright colors just like me, then these pebbles will be great additions to your tank.
Apart from aquariums, pebbles are also useful in the garden. You can place a couple of these pebbles around your flower bed to make them glow even in the darkest of nights. I used these pebbles to line the pathway leading to the front door, making it look like something out of a storybook.
I do have a couple of problems, though – one of which is that these pebbles are not that dense. I put a couple of these pebbles in an aquarium occupied by tetras and other small fish, and they had no problem moving these rocks around, which messed up my arrangement.
2. Lifegard Aquatics Dragon Rocks
I was surprised at how many rocks came in this package. Although the description says that it is just enough for a 10-gallon tank, I still needed to leave a couple out of the tank. The freshwater aquarium rock decorations that I did use were a bit too big so I still needed to trim them down a bit so they would fit my tank.
These are all-natural rocks. This means no two pieces will be exactly alike, and this adds to their natural charm. You can make your aquarium look like it was taken directly from underneath the sea, as you can make these rocks look like corals. Your imagination will be the only thing holding you back.
Also, because these are all real rocks, you don’t need to worry about any harmful chemicals leaching into the water. The only thing that you need to do before you place these rocks in your tank is to rinse them thoroughly. You do not need to do any additional treatments.
The thing I liked the most about these Dragon rocks is that they have a lot of holes and cavities. This made them a natural hiding place for the little fish. Also, because they have spaces at the base, even medium-sized fishes have somewhere they can hide and rest for a bit.
If you are a seasoned aquarist, then you will be glad to know that these rocks, due to them being very porous, are easy to shape and trim to size. If you need the rocks to be a specific shape, then you can rest assured that they are soft enough that a regular chisel will do the job well.
One thing I hoped the seller would have done, though, is pre-wash the rocks. I knew that they would have a bit of dirt on them as they were natural rocks, but most of them have a thick layer of caked-on clay, which was quite a challenge to remove. I suggest that you soak the rocks in a bucket of water before washing them.
3. WAYBER Pebbles Crystal Quartz Stones Rocks
I chose the black pebbles because I am going for a monochromatic look for my tank. However, I did glance over the other colors and now I am planning to start another tank, but this time, using the translucent pink pebbles. Whatever your personal color preferences are, you will find them here.
I was quite surprised to find out that these brightly-colored freshwater aquarium rocks were natural stones. I thought that these were made of resin. They are quite dense so they will not move around the tank even if you have a high-flow tank. Even the fish may have a hard time moving them around.
Speaking of the fish, they usually like to play or burrow into the substrate. If you used gravel with sharp edges, then it could hurt your fish. This is not a problem with these pebbles as they are all polished to eliminate any jagged edges, so they are perfectly safe for your fish to play in.
These pebbles came already somewhat cleaned. I still needed to rinse them under some running water, but not that much. Other natural decorative pebbles, especially the ones that were crushed and sifted, contain a lot of sand. These barely had any dust on them so they were easy to clean.
Aside from aquariums, I have found other uses for these pebbles. For instance, these make a great ground cover for potted succulents. These pebbles are also great as decorative media for air plants. I also use them in my clear flower vases. They hold the stems of the flowers and they look great.
These are real rocks, so they are quite dense. With that said, you should not expect to get a lot of rocks in a single package. At best, they could be enough to cover the bottom of a betta tank. If you want to use them in, say a 10-gallon tank, then you would need to buy a dozen or so packages.
4. Caribsea Life Rocks
Live rock is a must-have if you want to set up a reef aquarium, but real ones are quite expensive, and you would not want to even get near the illegally harvested ones. The Caribsea Life Rock is an environmentally friendly alternative as it is an artificial rock made to look and behave like a real live rock.
Although Caribsea says that their live rocks for freshwater aquariums do not need any curing, it is still important to give them a good washing in clean water before putting them in your tank. However, once all the sand and bits of paper are off, it is already safe to place the live rocks in your established reef tank.
The nice thing about this product is that it is not just a simple slab of plaster. The manufacturer infused it with spored beneficial bacteria. This means that they are technically live rocks. The bacteria will lay dormant while the rock is dry. They will also become active again when submerged in saltwater.
Although these are fake rocks, there is no risk of them contaminating your tank with harmful chemicals. Even the paint used to color the “rocks” is eco-friendly. I have been using these live rock substitutes for a couple of months and so far, I haven’t noticed any negative effects in my reef tank.
The best thing about this product is that it is significantly more affordable compared to real live rock. You will be getting a bunch of these faux live rock for the price of just one piece of the real thing. If you have barely enough left in your budget for setting up a reef tank, then I think this is a great choice.
Although I liked these live rocks a lot, I am not that impressed with their colors. They may have started out having vibrant colors, but they look a bit sun-bleached at the end of the manufacturing process. Also, if a piece of the rock breaks off, the inside is very white, like chalk.
5. CFKJ Aquarium Gravel River Rocks
Although I am not against colored resin rocks, there is no beating the natural beauty of real river rocks. If there are no rivers or streams near where you live, these stones are great substitutes. They are all-natural but they are polished to make them look even more beautiful.
These rocks for aquariums freshwater are just the right size and weight for an aquarium. You will also be getting different colors and shapes of rocks, so they will look natural when you use them to line the bottom of your tank. I like how non-uniform these pebbles are, but each piece is still relatively the same size.
Unlike artificial pebbles, these products have colors that will never fade. These are real river rocks and their colors are all-natural. This means they will still look the same even after many years have passed. This also means that you can reuse them indefinitely.
These pebbles come in an 18-pound bag, which is enough for a 20-gallon tank. I used this product as a second substrate layer, with a layer of sand underneath. I feel that 18 pounds of these pebbles are more than enough because I like to leave some spaces open. It just looks more natural that way.
I got two bags of this stuff, one is for my aquarium and the other I used as a top cover for my succulent collection. These did a great job of keeping the wind from blowing away the potting mix. Aside from that, they made my plants look even more amazing. You can also use these pebbles for landscaping purposes.
Take note that you have to wash the stones in hot water and some vinegar before you place them in your tank, though. These rocks have a thin layer of wax (to make them shine) so you need to wash them off to keep the fish safe. This is not that difficult to do. It will just take roughly half an hour to clean the entire bag.
6. Small World Slate Natural Slate Stone
I used these slate stones to create freshwater aquarium rock formations and they turned out quite well. These stones average around 2-3 inches in size, which is perfect for a 10- or 20-gallon fish tank. I used them to create caves and stacked stones, and they looked great.
Because these stones are flat, they make the perfect “building blocks” for creating aquascapes. These stones are quite solid and do not easily chip, so you can stick them together using aquarium-friendly superglue. You can then expect them to hold tightly for many years.
These are not faux stones. They are real slate stones, so they do not contain any harmful chemicals or substances. Moreover, they do not contain any harmful parasites. However, you should still give these stones a good rinsing and scrubbing beforehand to prevent your tank from getting cloudy.
Speaking of cleaning, these stones are not that hard to prepare for use. I just placed them inside a bucket of water for an hour or so to loosen any caked dirt. After that, I scrubbed the surface gently. The entire process took around three hours, but it is not labor-intensive at all.
I should warn you, though, that these stones have rather jagged edges. You may not want to use these stones with fish that have long, flowing fins, like bettas or goldfish because of that.
7. BLQH Pebbles Aquarium Gravel River Rocks
The nice thing about using white pebbles in an aquarium is that they frame the other contents of the tank. For instance, if you have a small betta tank, placing white pebbles will make the fish’s colors pop. In addition, you do not need to use a strong light. The pebbles’ color will help keep the tank bright.
These rocks are also all-natural. This means they do not contain any chemicals that may contaminate the water in your fish tank. Also, since they do not come from rivers or ponds, you can be sure that they do not have any harmful parasites that can harm your fish.
If you like taking care of live plants in an aquarium, this is the perfect substrate to use. These pebbles are perfect for live plants as their roots will have plenty of space for growth. These pebbles are also dense, thereby preventing the plants from getting uprooted.
This product comes in an 18-pound bag, which contains more than enough pebbles for a 10- to 20-gallon tank. I used this on my 15-gallon tank and it made a layer that is at least 2 inches deep. It might be a stretch to spread this out on the bottom of a 20-gallon tank though, so you may need a bag and a half.
Don’t worry about the half bag of white pebbles leftover from your aquarium. There are plenty of other uses for these pebbles. I use these as ground cover for my succulents, and they also make great vase fillers, especially if you have a translucent vase.
I do have a bit of a problem with this product and that is it takes a long time to clean for first-time use. There is so much dust and sand in the bag of pebbles that it will take at least 4 to 5 buckets of water before the gravel is clean enough for use in your aquarium.
8. BCQLI Sphere Bio-Filter Red Volcanic Rocks
These rocks are the real deal. If you are thinking of adding a bit of color, and also a few nitrifying capabilities in your aquarium, then I think these are just the things that you need. I scattered a bit of them in my aquarium, which added a bit of brightness to the tank.
Because lava rock is naturally porous, they are great for cultivating essential nitrifying bacteria. This means that these rocks are cleaning the water in the tank just by being there. You can add these rocks in there and in a couple of weeks you will find that the nitrate level in your tank will remain healthy and stable.
These rocks are mainly sold for use as a filter medium. By using these rocks as filter media, they can also filter solid waste and debris. The best thing about them is that compared to cloth filters, you do not need to replace them every couple of months or so.
It also does not matter if you have a freshwater or saltwater tank. You can use the rocks just fine. These rocks came from a quarry, so there is no need to fret about salt particles getting into your freshwater tank. However, if you will be using them with a marine tank, then you should also have a protein skimmer.
Lava rocks are also great for gardening, especially if you are taking care of succulents. Add these rocks into regular gardening soil and it will turn into fast-draining soil, which is ideal for succulents and the like. You can also use this to cover the top of the potting mix to prevent air erosion.
Now, here is the problem. If you are thinking of getting this product with the intention of using it as a substrate, don’t bother. You will only be getting a small bag that contains just enough rocks for an overhead filter. If you want lava rocks to cover the bottom of the tank, you can find them cheaper elsewhere.
9. Voulosimi Lava Volcanic Rocks
I must warn you that this specific product can be pricey, but it does look great in an aquarium. These lava rock granules provide your fish with a uniform monochrome background that lets their colors shine. If you spent hours just watching your fish, prepare to spend a lot more time when you use this as a substrate.
If you do use this product as an aquarium substrate, the spaces in between the pebbles are big enough that they will let solid waste pass through until they reach the bottom. This will allow beneficial bacteria to deal with ammonia and nitrates. It would be like having another under gravel filter in your tank.
If you like taking care of live plants, then these pebbles are among the best ones that you can use. The roots of the plants will have enough room to grow and expand. Moreover, the pebbles are heavy enough that they can securely anchor the plants in place.
These pebbles are the ideal breeding ground for beneficial bacteria, the ones that help with the nitrification process. Each pebble has a lot of surface area, so there are more places where the bacteria can grow. This means that they can help get rid of the ammonia in the water.
Aside from aquarium use, I also found that these pebbles are ideal for use in succulent planters. I mix them with equal parts of garden soil to turn it into fast-draining soil. This is the ideal planting medium for succulents as these kinds of plants do not like to sit in a pot of soggy soil for a long time.
Here is the catch. The pebbles are a bit on the expensive side. You will only be getting a rather small bag, which does not have nearly enough pebbles to cover the bottom of a 5-gallon tank.
10. KISEER Mini Clear Glass Stone
These tiny little glass beads look like tiny gemstones. Adding a bit of these little sparklers in certain parts of your aquascapes will add quite a bit of charm and whimsy to your setup. They also come in a lot of different colors, so you can mix and match them if you want.
Even though these pebbles are made of glass, they are quite small and they do not have any jagged edges on them. This means that the pebbles are completely safe for your fish. Even if your fish were to ingest these pebbles like they usually do, they will not be in any danger and they will just pass through their system.
If you think that your aquascape is a bit bland and needs a bit of color, these pebbles are the perfect addition. Also, if you are following a certain theme in your aquarium, you can choose from any of the vibrant colors available. Because these beads are made of glass, their colors will never fade.
Unlike other aquarium pebbles, these glass beads are much easier to clean. Unlike real stones, these glass beads do not come covered in their weight in sand, so you will only need to rinse them a couple of times before they are clean enough for use in your tank.
Just like the other products in this list, you can also use these glass pebbles for other decorative purposes. Because I liked how they look, I got another bag just for my clear flower vase. The beads are excellent when used as a vase filler.
If you are thinking of using this product as an aquarium substrate, you will be disappointed at the size of the bag. You will not get nearly enough to even cover half of the bottom of a 5-gallon tank.
What to Look For When Buying a Rocks for Freshwater Aquarium
If you are shopping for aquarium rocks and pebbles, then here are some of the qualities that you need to keep an eye out for.
Value for Money
If you are thinking of using pebbles as a substrate for your aquarium, make sure that you will be getting your money’s worth. You should get enough pebbles to provide at least a two-inch deep layer.
If you want to get the most out of your money, get rocks that are porous and full of holes. They make ideal breeding grounds for beneficial bacteria that help break down ammonia and nitrate. It will be like having another filter cleaning the tank.
Pick the kinds of rocks that will work well with the theme that you are going for in your aquarium. For instance, will you be doing a fantasy-themed tank? Use brightly-colored pebbles or gravel as a substrate. Are you planning a seascape? Use slate stones to create cliffs and other natural features.
Whatever kind of theme you have planned, you can be sure that there are plenty of rocks and stones that can help you achieve it.
Make sure that you will be getting safe rocks for freshwater aquarium. There are some stones and gravel that are only for gardening and decorative purposes. The main reason is that they might contain harmful substances. Only use natural stones or those that are safe to use in your aquarium.
Frequently Asked Questions
What Rocks are Safe for a Freshwater Aquarium?
Typically, any rocks or stones that came from riverbeds are ideal for freshwater aquariums. You can also use anything that came from a quarry.
Where to Get Rocks for a Freshwater Aquarium?
Aside from pet supply stores, you can also get rocks that you can use either for decorations or substrates from any gardening or landscaping supply store. Just make sure that you are getting stones that are freshwater-safe.
There are so many different kinds of rocks and stones that you can use in your aquarium setup that you might fill up your tank too much if you are not careful. To prevent your tank from getting overrun by geodes, you need to find the best rocks for a freshwater aquarium.
Stones and rocks might have seemed boring for you at one time, but now that you know how to use them in an aquascape, I am sure that you cannot have nearly enough of them.