Coldwater aquariums plants are generally considered plants that that can be easily maintained at least at room temperature without an aquarium heater. Basically, in the aquariums, their water temperature should be just about the standard room temperature or slightly lower.
Such aquariums can be regarded as unheated aquariums; they feature temperatures ranging from 61 – 70 °F (16 – 21 °C), and as such distinct from tropical aquariums which have temperatures as high as 82 °F (28 °C).
That said, before setting up or aquascaping a coldwater aquarium, you should first consider live plants that can tolerate lower temperatures; as low as the 60s (measured in Fahrenheit).
Many live aquarium plants fit in this category, but here are some of my top picks:
- Fairy moss
- Water hyacinth
- Anacharis
- Marimo Moss Ball
- Dwarf Hairgrass
- Duckweed
- Vallisneria
- Amazon Frogbit
- Java Moss
- Crystalwort
- Java Fern
- Brazilian Micro Sword
- Marsilea Hirsuta
- Pearlweed
- Subwassertang
1. Fairy moss (Azolla spp.)
Let’s start from the champions – Fairy moss or Mosquito fern. We often use plants in our aquariums but do not know the story behind them.
Do you know that these species caused Ice age on the planet?
Azolla spp. can withstand a wide range of temperatures, from 41 °F (5 °C) to as high as 113 °F (45 °C).
This is an extremely fast-growing floating plant and can be easily kept in coldwater tanks.
Generally, the plant is green but under full light exposure, it gets an intense reddish coloration.
Fairy moss Basic Requirements:
- Water pH: 6.0 – 7.5
- Hardness: Soft to hard water
- Temperature tolerance: 41 – 113 °F (5 – 45 °C)
- Lighting: Moderate
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2. Water hyacinth
Water hyacinth (Eichhornia crassipes) is another extremely adaptable plant that can be found in our hobby.
Actually, this plant is so hardy that it is listed among the 100 worst invasive plants in the world.
Water hyacinth can survive under harsh conditions and tolerate water temperature from 50 – 104 °F (10 – 40 °C).
This is a free-floating aquatic plant with bright green coloration and beautiful, six-petaled violet flowers.
Keep in mind that this is a large plant. Its leaves measure roughly 4 – 8 inches (10 – 20 cm), so they cannot be kept in small tanks.
Water hyacinth Basic Requirements:
- Water pH: 6.0 – 8.0
- Hardness: Soft to hard water
- Temperature tolerance: 50 – 104 °F (10 – 40 °C)
- Lighting: Moderate to High
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3. Anacharis (Egeria densa)
Egeria densa, commonly known as Anacharis, has become very popular in the aquarium hobby.
Unfortunately, its ability to tolerate temperature and different water parameters are so strong that you need to make sure it is not banned in your state and you do not buy or sell it illegally.
Even though the optimum temperature for Anacharis is 70 °F (21°C), it can tolerate temperature as low as 59 °F (15 °C) and as high as 82 °F (28 °C). Moreover, this species has some degree of tolerance even for cold waters. It can survive winter in a ditch under a cap of ice. However, freezing is lethal.
Anacharis is usually a foot or two long but can be much longer with the small strap-shaped leaves on the stem.
Anacharis Basic Requirements:
- Water pH: 6.0 – 8.0
- Hardness: Soft to hard water
- Temperature tolerance: 59 – 82 °F (15 – 28 °C)
- Lighting: Moderate to High
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4. Marimo Moss Ball
This species is a type of green algae named Aegogropila linnaei, famous for its use in the aquarium hobby.
Marimo is not a true moss; instead, it is a species of filamentous green algae found in cool lakes in the northern hemisphere. This species is known by several names such as lake ball, mossimo, cladophora ball, lake ball pets, etc. It is employed in the aquarium for beautifying the foreground and midground.
Marimo is notable for its temperature tolerance; it can survive between 43 – 75 °F (6 – 24 °C) without any significant issues.
This species is perfect for improving the aesthetical quality of a variety of tanks as it features a fluffy, velvety spherical ball with bright, deep green color.
Its natural habitats include cool freshwater and brackish lakes; this reveals that Marimo would have no problems growing in a cold water tank. I consider Marimo to be a special plant that can thrive in various tanks and water conditions.
Marimo Moss Balls Basic Requirements:
- Water pH: 7.0 – 8.0
- Hardness: Soft to hard water
- Temperature tolerance: 43 – 75 °F (6 – 24 °C)
- Lighting: Low to Moderate lighting
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5. Dwarf Hairgrass
Dwarf hairgrass (Eleocharis sp.) is a versatile and hardy plant noted for its use in creating thick carpets in aquariums. The plant is characterized by short stature, needle-like green leaves, and durability.
Dwarf hairgrass is undoubtedly one of the best carpeting plants in the hobby, and it is recommended for both beginner and advanced aquarists. This species is equally known as DHG, needle spike rush, needle spike sedge, and spike rush.
Eleocharis sp. Makes my list of top coldwater aquarium plants because of its remarkable ability to thrive in a wide range of temperatures – even colder temperatures like 50 °F (10 °C).
The plant requires moderate–high lighting to stay healthy and maintain a bright green coloration in the aquarium. I must say that planting Dwarf hairgrass is a bit tasking, so you should be ready to put in some effort to have this species growing optimally in your aquarium.
Dwarf Hairgrass Basic Requirements:
- pH: 5 – 7.5
- Water Hardness: Soft to hard water
- Temperature tolerance: 50 – 77 °F (10 – 25 °C)
- Lighting: Moderate to high
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6. Duckweed
It’s always mixed reactions whenever the species – some people love it some people hate it. Nonetheless, I have to include this plant in the list as it can be used in cold water tanks.
Duckweed (Lemnoideae sp.) grow optimally in water temperatures between 15 and 32 °C (60 – 90 F). Above or below that range, Duckweed just sort of sits there and does not grow.
Duckweed (Lemnoideae) is an amazing aquarium plant as it can thrive in a wide variety of tank setups. Also, the plant tolerates various aquarium conditions, and it is capable of consuming huge loads of ammonia and nitrates in the tank, making the water cleaner and safer.
Duckweed tends to form dense mats or colonies on the water surface quickly when it settles in the tank. These mats provide shade/shelter to aquarium inhabitants and also perform other beneficial roles.
Also, the plant features numerous small, organized thallus or frond structures, about 0.3 inches long. And the fronds can attach to one another, thus assuming the look of an extensive mat or blanket on the water surface.
Duckweed Basic Requirements:
- Water pH: 6.5 – 7.5
- Hardness: Soft to hard water
- Temperature tolerance: 60 – 90 °F (15 – 32 °C)
- Lighting: Moderate to High
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7. Vallisneria
Vallisneria is one of the most renowned plant species in the hobby. The plant is easy to cultivate and very undemanding. This is another great candidate for a cold water tank.
Vallisneria is ideal for background placement in planted tanks and it exhibits a relatively moderate to fast growth rate which most aquarists love.
This species will appreciate optimal water temperature between 68 – 82 °F (20 – 28 °C). However, it is also known to tolerate temperature in the range of 15 – 30 °C (59 – 86 °F) as well.
One of the great things about Vallisneria is versatility. Even though it is a root-feeder plant, it still absorbs a great portion of nutrients from the water. So, as long as your animals produce enough waste, you might not even need to add any fertilizers.
Vallisneria Basic Requirements:
- Water pH: 6.5 – 8.0
- Hardness: Soft to hard water
- Temperature tolerance: 59 – 86 °F (15 – 30 °C)
- Lighting: Moderate
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8. Amazon Frogbit
Limnobium laevigatum, also known as Amazon frogbit, is an aquatic plant prized for its vast usage in aquascaping. Amazon frogbit is a perennial flowering plant capable of surviving in almost all kinds of freshwater habitats.
This species is indigenous to Central and South America. It grows in freshwater habitats with soft water and high lighting. Due to the plant’s ability to thrive in a range of aquarium conditions, including lower temperatures down to 61 °F (16°C), this species is considered ideal for a coldwater aquarium setup.
Amazon frogbit is characterized by a near-perfect or circular structure, bright green leaves, smooth & unmarked leaves, fuzzy branching roots with trailing roots, and the presence of spongy aerenchyma tissue on the underside of the leaves (helps in buoyancy).
The plant is cultivated by floating on the surface of the water, and it reproduces by stem fragmentation, forming plantlets set off through ramets or stolons.
Amazon Frogbit Basic Requirements:
- Water pH: 6.0 – 7.5
- Hardness: Soft to moderately hard water
- Temperature tolerance: 64 – 80 °F (18 – 26 °C)
- Lighting: Moderate to high lighting
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9. Java Moss
Java moss, Taxiphyllum barbieri, is a popular aquatic plant used in decorating aquarium setups. This species is prized for its versatility, aesthetic values of care, and easy propagation.
Native to tropical regions in Southeast Asia where it grows on rocks and tree trunks in rivers and streams.
Java moss is yet another ideal species for adorning coldwater tanks since it can thrive in water temperatures as low as 15 °C (59 °F).
This plant doesn’t need a substrate to grow — it is moss and can be grown by attaching it to various hard surfaces (stones, gravel, driftwood, bogwood, and other aquarium décor). Java moss can be cultivated in a 5-gallon tank, and it thrives in low to medium lighting intensity.
Java moss is best placed in the foreground or midground in freshwater or brackish water tanks. Also, it can thrive without fertilizer application and supplemental CO2.
Java Moss Basic Requirements:
- Water pH: 6.0 – 9.0
- Hardness: Soft to hard water
- Temperature tolerance: 59 – 90 °F (15 – 32 °C)
- Lighting: Low to Moderate lighting
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10. Crystalwort
Crystalwort (Riccia fluitans) is a great beginner plant. This is a bright green plant that was made popular by the renowned aquascaper Takashi Amano.
Generally, Riccia fluitans is a floating plant. However, it can be kept underwater if there is pressurized CO2.
Crystalwort can survive in waters with temperatures 59 – 86 °F (15 – 30 °C). Therefore, hobbyists will not find it difficult to grow Riccia fluitans in their tanks.
Crystalwort Basic Requirements:
- Water pH: 6.0 – 8.0
- Hardness: Soft to moderately hard water
- Temperature tolerance: 59 – 86 °F (15 – 30 °C)
- Lighting: Moderate to High
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11. Java Fern
Java fern is a popular aquarium plant and, unarguably, one of the easiest live plants to grow in a freshwater tank. The species is low maintenance, hardy, undemanding, and versatile.
This plant is native to Java (Indonesia), where it grows attached to rocks, ground, and tree trunks. Besides its native site, the species is also widely distributed in tropical Southeast Asia (Philippines, Thailand, Malaysia, and some parts of China). It grows luxuriantly in tropical rainforests, coastal brackish regions (thus, it can be used in brackish water tanks), banks of freshwater streams, and rivers.
Java fern is a green-colored plant with a leathery texture and adorned with veiny black lines. Its coloration varies depending on the intensity of the lighting provided.
The preferred temperature is between 20 – 28 °C (68 – 82 °F), but I have witnessed this species growing in a cold water tank with a temperature of 64 °F (18 °C).
So, whether tropical or coldwater aquaria, Java fern will adapt and thrive if optimal conditions are met. You may cultivate this plant in your cold water tank by attaching/fastening the rhizome to the desired hardscape using tapes, adhesives (aquarium glue), or fishing wire.
Java Fern Basic Requirements:
- Water pH: 6.0 – 8.0.
- Hardness: Soft to hard water.
- Temperature tolerance: 18 – 28 °C (64 – 82 °F)
- Lighting: Low to Moderate lighting.
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12. Brazilian Micro Sword
Lilaeopsis brasiliensis (Brazilian micro sword) is one of the hobby’s smallest and highly ranked carpet plants.
This plant is loved by aquarists because of its small form, hardiness, tolerance, and excellent carpeting ability. In addition, this is an excellent spawning medium for fish and dwarf shrimp.
Brazilian micro sword is relatively easy to grow and ideal for aquascaping the foregrounds of freshwater aquaria. The plant forms a lush green carpet that covers the substrate densely and creates a visually appealing impression in planted tanks that do not exclude coldwater ones.
Brazilian micro sword is one of the most suitable species for coldwater tanks since it can survive in temperatures ranging from 18 – 25 °C (64 – 77 °F).
This species grows relatively slowly and requires a nutrient-rich substrate and moderate to high lighting to put out beautiful, thick tufts on the aquarium substrate.
The plant is cultivated by rooting the stems in the substrate (about ½ inch deep). Propagation is through the production of stolons/runners that bear independent daughter plants.
Brazilian micro sword Basic Requirements:
- pH: 6.0 – 8.0
- Water Hardness: Soft to hard water
- Temperature tolerance: 64 – 77 °F (18 – 25 °C)
- Lighting: Moderate – high
Brazilian Micro Sword Care Guide – Planting, Growing and Propagation
13. Marsilea Hirsuta
Marsilea hirsuta is an undemanding carpet plant ideal for creating lush, dense, green carpets in the background of planted aquaria.
This is a fascinating ground cover plant owing to its strong carpeting ability. Marsilea hirsuta is a slow-grower, maintains a compact size of only a few centimeters/inches, and forms thick beautiful carpets by spreading its prolific runners all over the aquarium substrate.
The species is ideal for beginner aquarists because of its low maintenance. Also, it is a great alternative to live aquarium plants like Glosso, Monte Carlo, and Dwarf baby tears.
Marsilea hirsuta features thin stems that bear a two-part, three-part, or four-part frond, usually in a low form when established in the tank. The plant thrives in aquatic environments with a temperature range of 64 – 77 °F (18 – 25 °C), making it suitable for coldwater tanks.
Marsilea Hirsuta Basic Requirements:
- pH: 6.0 – 7.0
- Water Hardness: Soft to hard water
- Temperature tolerance: 64 – 77 °F (18 – 25 °C)
- Lighting: Moderate
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14. Pearlweed
If you are looking for a plant that can be grown as a foreground, mid-ground, background, float, or even as a terrestrial form, you have found one.
This is probably one of the most versatile plants in the hobby.
Pearlweed (Hemianthus micranthemoides) is a low-maintenance plant that can tolerate temperatures ranging from 66 – 82 °F (19 – 28 °C).
When optimal conditions are met, this plant will grow so fast you will have to cut it back weekly.
Pearlweed Basic Requirements:
- pH: 6.5 – 7.5
- Water Hardness: Soft to hard water
- Temperature tolerance: 66 – 82 °F (19 – 28 °C)
- Lighting: Moderate
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15. Subwassertang
An interesting fact about this plant is that it does not even have a scientific name yet. Even more, biologists acknowledge the fact that they are unaware of any record where this plant has been observed naturally growing in aquatic environments.
According to the study, it was assumed that all of the plants currently being sold are exact clones of each other and have reproduced entirely by continuous meristematic growth.
Nonetheless, this mysterious plant came to our hobby in the early 2000s and has developed a reputation as a hardy plant that does not require almost any care.
Subwassertang grows best in the temperature range of 68 °F to 75 °F (20 – 24 °C) but can thrive in colder temperatures as well.
Subwassertang Basic Requirements:
- pH: 6.0 – 8.0
- Water Hardness: Soft to hard water
- Temperature tolerance: 64 – 75 °F (18 – 24 °C)
- Lighting: Moderate
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In Conclusion
Although the aforementioned live plants are mainly used to adorn tropical aquariums, they are excellent candidates for established coldwater aquaria.
These species can survive warm temperatures and cold temperatures in a captive environment, so consider them viable options when setting up your coldwater tank.
| Plant Species | Temperature tolerance | |
| 1 | Fairy moss | 41 – 113 °F (5 – 45 °C) |
| 2 | Water hyacinth | 50 – 104 °F (10 – 40 °C) |
| 3 | Anacharis | 59 – 82 °F (15 – 28 °C) |
| 4 | Marimo Moss Ball | 43 – 75 °F (6 – 24 °C) |
| 5 | Dwarf Hairgrass | 50 – 77 °F (10 – 25 °C) |
| 6 | Duckweed | 60 – 90 °F (15 – 32 °C) |
| 7 | Vallisneria | 59 – 86 °F (15 – 30 °C) |
| 8 | Amazon Frogbit | 64 – 80 °F (18 – 26 °C) |
| 9 | Java Moss | 59 – 90 °F (15 – 32 °C) |
| 10 | Crystalwort | 59 – 86 °F (15 – 30 °C) |
| 11 | Java Fern | 18 – 28 °C (64 – 82 °F) |
| 12 | Brazilian Micro Sword | 64 – 77 °F (18 – 25 °C) |
| 13 | Marsilea Hirsuta | 64 – 77 °F (18 – 25 °C) |
| 14 | Pearlweed | 66 – 82 °F (19 – 28 °C) |
| 15 | Subwassertang | 64 – 75 °F (18 – 24 °C) |