If there’s one feature of planted aquaria that eludes most people, it’s being able to use freshwater carpet plants. For those seeking to fill their tank with green, it’s usually the final challenge before they can focus wholly on aquascaping. Let’s dive in with 7 of my favorites, and then we’ll go over how to make them thrive in your tank!
Table of Contents
1. Riccia Fluitans
- Ideal pH: 6-7.5
- Lighting Required: Medium
- Difficulty: Intermediate
- CO2: Recommended
Riccia is sometimes used as a floating plant, but these days it’s much more common to find it placed in the bottom of a tank. It was popularized as a carpet plant by Takashi Amano initially, but today it can be found in many tanks.
Riccia is hardier and less picky than the majority of carpet plants out there. It can handle fluctuations in water quality better than most, running from a softer pH of 6 to around 8. I’d recommend keeping your pH under 7.5 for the health of other plants and fish in the tank.
Once planted and acclimated to a tank, Riccia fluitans grows rapidly. Many people have failed to achieve great results with it for an entirely different reason than most carpet plants fail to thrive, however.
It won’t stay down on its own.
Instead, when you install Riccia as a carpet plant, you need to affix it to a slate or a stainless steel mesh(plastic works as well). It doesn’t “root” like most mosses, so I much prefer to work with meshing. It’s simple, sandwich the initial culture of Riccia between two pieces of mesh. From there, you can allow it to grow.
Careful pruning is needed to use it long-term. If the portions contained in the mesh don’t receive light, then they’ll eventually die and let the whole mat loose. This makes it rather high maintenance, despite the lack of demands on water quality.
2. Sagittaria Subulata
- Ideal pH: 6.5-7
- Lighting Required: Medium to High
- Difficulty: Intermediate
- CO2: Recommended
A personal favorite is Dwarf Sagittaria. This attractive plant will look familiar to anyone familiar with the Echinodorus genus of plants and grows similarly. The cool part is that the right water conditions will cause it to grow in dense, tightly packed formations.
This makes it suitable as a base layer for jungle tanks. The long and comparatively thick fronds create a more dramatic texture along the base of the tank. It’s less touchy than some carpet plants. On the other hand, don’t be fooled into thinking that it will create a fantastic base without some extra work.
Dwarf Sagittaria tends to grow higher than many carpet plants, and there’s no real way to trim it down too much without compromising the plant. It’s often used to break visual lines along the aquascape, especially in higher tiers, while the lower areas are populated with lower plants.
It’s relatively low maintenance, however, since it tends to grow lower than many of the carpet plants available. In most cases it will average around 3-5” tall, making a suitable carpet for tanks of 20 gallons and larger but in extreme cases it will reach up to 12”. That means you’re doing great, but will also require you to thin it out, at least in the foreground, if a carpet was the intended effect.
3. Glossostigma Elatinoides
- Ideal pH: 5-6.5
- Lighting Required: Very High
- Difficulty: Advanced
- CO2: Required
Glossostigma is not only beautiful, but it’s also the perfect carpet plant. It grows thickly, quickly, and naturally to create a lush carpeting for the bottom of the tank. The biggest problem? Most people can’t seem to get it to grow.
Here’s the thing: Glosso requires a low pH, low kH, and extremely high lighting. It also requires some form of CO2 input to maintain density. If any of these factors are off, the plant will either become spindly and weak. If more than one is off? It will die.
It also requires high levels of iron. Ideally, you can allow it to come from the substrate. Take a look at the micronutrient content of your gravel or sand before you commit to growing Glosso. If the iron content is low, but you still need Glosso in your tank, then it’s time to take a look into root tabs.
Glossostigma elatinoides is a hard plant to grow. Even advanced aquarists sometimes have trouble with it, but if you’re willing to do the work, it’s also rewarding. Give it a shot if you’re willing, the worst that will happen is you’ll learn a lot from experience.
4. Hemianthus Callitrichoides
- Ideal pH: 5-7
- Lighting Required: High
- Difficulty: Advanced
- CO2: Required
Hemi is also called Dwarf Baby Tears. Hemianthus callitrichoides is one of the smallest plants that go into freshwater aquariums. It’s also an excellent carpet, provided that its needs are met. This particular variety hails from Cuba.
As long as your requirements are in place, it’s an easy plant to manage. It does grow much slower than many carpet plants. Due to that factor, you’ll need to be strategic about placing it. I prefer to place the clumps 3-4cm apart in the substrate, waiting for them to grow in and create coverage in empty space.
My favorite part about this plant? It’s practical. Dwarf Baby Tears, under high lighting, provide the perfect cover for both fish fry and shrimp. Due to the 2 watt per gallon requirement, you can use a single fixture for multiple small tanks.
It’s my go-to for dwarf shrimp breeding tanks, combined with a single rock in 5 gallon tanks it creates an attractive look on top of being quite practical.
I would consider all of the Hemianthus genus to be advanced plants. That said, it has more to do with easily controllable factors such as light than requiring a ton of micronutrient tweaking. Do your research and it’s easy to handle.
5. Micranthemum Tweediei
- Ideal pH: 5.5-7.5
- Lighting Required: Medium
- Difficulty: Intermediate
- CO2: Recommended
Do you like the look of Hemi, but aren’t sure if you’re ready to conquer it just yet? If so, then you may want to take a closer look at Micranthemum tweediei, or Monte Carlo. This Argentinian plant is relatively new to the scene, and there was originally some confusion about its genus and name.
That said, it seems to grow exceedingly well in pretty much any tank. Denser mats are possible if you opt to go with high lighting, but it grows well in almost every set of conditions imaginable. It’s not quite as easy as Elodea densa, but it’s close.
In most cases where it fails to thrive, the problem is pH or kH. Keep the water soft and acidic, and you’ll really only need to keep it trimmed.
The trimming is where Monte Carlo gets you. If you don’t keep the plant trimmed down and thinned out in high light tanks, it has a dirty little secret: it will strangle the bottom pieces of the plant.
Keep it trimmed regularly. If you trim and keep the water in the correct parameters, then it’ll grow very quickly. Very quickly, so don’t buy too many cultures when you’re originally setting it up. It’s a high maintenance plant, but not a particularly hard one to grow.
6. Marsilea Minuta
- Ideal pH: 6-7.5
- Lighting Required: Medium
- Difficulty: Advanced
- CO2: Required
A low-growing aquatic fern, Marsilea minuta, is a fast favorite for many aquarists. It’s also known as Dwarf Water Clover. This plant is a bit demanding, but once settled in is a beautiful and unique carpeting plant. It can also be used floating if that’s what you’re looking for.
This African-native plant looks exactly like clover for the most part. That said, the features are a bit large for very small tanks. I’d only keep it in tanks which are 10 gallons or more. Otherwise, the texture is rather overwhelming.
The key to growth? Soft water, low pH, and a lot of patience. Dwarf Water Clover is slow-growing when compared to many of the plants on this list. The truth is that patience is your biggest ally, and many only use it in small portions of their aquascape.
In larger tanks, I’ve found it’s perfect for crevices in rocks and large holes in driftwood. It does carpet well; it just takes much longer than most others. In hard-to-reach portions of the tank, this can be a feature rather than an aggravation since it reduces the amount of trimming required.
Give it a shot either way. It’s low-maintenance and rewards the patient aquarist with dense, beautiful growth.
7. Eleocharis Parvula
Image Source: https://meethepet.com/dwarf-hairgrass/
- Ideal pH: 6-7.5
- Lighting Required: Low (Recommended High)
- Difficulty: Intermediate
- CO2: Recommended
While the predominance of others in AGA tournaments overshadows some interesting plants, Eleocharis parvula remains one of my favorites. Call it Dwarf Hairgrass, call it Eleocharis. Whatever you call it, it’s one of the coolest carpets around, and if you’re able to get it to take off, then you’ll have a truly unique look going on.
The thin, grass-like blades of this plant grow easily once rooted. Runners will be sent out occasionally. But, if you’re trying to get it to thrive, I’d recommend ignoring the people who point out it can grow with low lighting and no CO2.
A dense carpet is only possible if you put in the work. High lighting and moderate CO2 allows for dense growth of this beautiful plant. You may need to bring the runners into check regularly, pulling them closer to the original plant.
If you check all of the boxes, the only concern is how long you want to keep your tank’s new lawn. It’s a favorite of mine and another of those I’ve used in breeding tanks on a regular basis. Try it out, especially if you’re a fan of overgrown “jungle” tanks.
Bonus Plant for Beginners: Java Moss
If you’re failing to get any of the “regular” carpet plants thriving, especially if it’s due to inadequate lighting or CO2, I recommend giving Java Moss a shot. It’s easy to find and even easier to grow.
The trick, in this case, is making it work as a carpet plant.
Use plastic or stainless steel netting like you would for Riccia. Java Moss tends to grow no matter what you throw at it, the webbing just holds it in place. Trim it down from there to where you’d like it to be.
Keep in mind that, like Riccia, this may not last forever. I’ve been able to make mats last up to 3 months in the past, but the portions of the plant holding it down will eventually die. That will let the clump of moss loose.
In that case, it’s no big deal. Just pull the netting, replace the Java Moss, and put it back down in the tank, and you’ll be fine.
See also: 9 Easy Aquarium Plants for Beginners
What’s the Minimum Needed for My Carpet Plants?
For many people, carpet plants seem to be something that only the advanced aquarist is able to pull off. Nothing could be farther from the truth.
The mistake that most people make is simply not having the right equipment. While plants like Glosso can be extremely touchy, I’d say half of the above aren’t all that picky when it comes to water conditions.
Instead, you need to look at what you’re putting down with your equipment and initial tank setup.
You need the following:
- Lighting: You need at least 2 watts per gallon for a dense carpet, no matter which plant you’re using. If you’re lower than that… look into alternative aquascape designs. Aim for 100 lumens per gallon if using LED lighting. 160 lumens per gallon is better.
- CO2: Some form of CO2 is necessary for dense carpets. If you’ve never had a CO2 setup, get prepared for some insane growth in all of your plants.
- Nutrient-Rich Substrate: No inert sands or gravels. You can layer your substrate, but you need something which is high in nutrients. Iron in particular, but macronutrients as well. Sand is better than chunkier substrates as well.
If you have the above in place, you’re on good footing. From there, you’ll need to experiment and see what works best for you.
There’s one caveat to the above: Flourish Excel can be used in place of a CO2 tank to avoid the high initial costs. I recommend only sticking with it long-term if you’re using a tank of 10 gallons or under, however, as Excel gets pricey and large tanks will require a significant amount of it.
You’ll also need proper filtration for the bioload in your tank. Nitrates should be under 10ppm, and preferably under half of that. Filtration is a tricky subject.
As a general rule, if your fish don’t require a slower environment(i.e., Betta, Gourami), then you can use up to twice what filters are rated for. So you could, for instance, run two Aquaclear 20 filters on a 20-gallon tank without producing an overly chaotic environment.
Learn more: 6 Steps to Set Up A Thriving Planted Aquarium
Making Your Living Carpet Thrive
With the basics in place, you’re off to a great start. There’s more to it than just having the right setup, however, and carpets are notoriously touchy.
A good understanding of micronutrients is what’s required to achieve world-class growth and density in your plants. CO2 is the basis of aquatic plant growth. Without carbon dioxide, there’s no form of carbon to allow your plants to grow.
The macronutrients are the NPK complex. Nitrogen, phosphate, and potassium. Most commercial fertilizers focus on these, and using them regularly is a good way to get started. Unfortunately, the instructions on the bottle may not be the best way to do things for your tank. Experimentation is the key to making a beautiful planted tank.
These nutrients are also provided by fish waste, particularly nitrogen.
Iron and manganese are the most commonly deficient micronutrients in planted tanks. Some substrates provide them, but you may need to dose them using specialized fertilizers when plants are particularly hungry for them. Lack of iron is often a cause of Glosso failing to thrive, for instance.
The other key is overall water parameters. Use your test kit on your water source to see where the pH sits. Most carpet plants do better in acidic conditions. Something in the range of 5.5-6 is much better than the higher end of the plant’s tolerated range.
Lastly, you also need to use softer water. This is a big place that many people fail. I’ve had issues with it well into my “advanced” days due to being stubborn. Softer water allows more CO2 to be created in the water stream.
Remember that planted tanks are a full biochemical system. I recommend checking this link to learn more about how to properly manage the whole system. There’s a lot more going on with all of these factors than most people are aware of.
Ready for a Challenge?
Creating a dense, lush carpet isn’t something that everyone can do right away. Get prepared to lose some plants, and have a couple of bumps along the way. But the truth is that being able to make freshwater carpet plants thrive is the final test before getting into advanced aquascaping. A lack of knowledge is all that holds most people back, are you ready for a challenge?
