In this article, I have put together the list of the most popular aquarium plants that can grow in brackish water tanks. So, if you want to know the details and numbers, it will help you out.
It took me a lot of time to check and verify data. As usual, I refer to the published studies and the experience of different aquarists.
I need to say that information on brackish water plants is scanty. So, if you have something to share with the community of aquarists, please send me the message and I will update the article.
Brackish Conditions
Ideally, brackish conditions are found in natural environments like an estuary; which is basically a partially enclosed, coastal water body where freshwater from rivers or streams mixes with saltwater from the ocean.
Besides estuaries, other known brackish habitats include mangrove forests or swamps, marshes, and lakes. The salinity of a brackish habitat is influenced by tidal cycles, inflow of freshwater, evaporation, and ice formation.
Also, brackish conditions can be replicated in an aquarium setting, and plants to be grown in such aquariums are those that can tolerate water with low concentrations of dissolved salts.
Keep reading for a list of suitable aquatic plant species that can be grown successfully in a brackish aquarium.
Limitations for Brackish Water Plants
Brackish water refers to water with more salinity than freshwater but less salinity than normal seawater. Essentially, freshwater holds less than 0.5 ppt (SG = 1.0004) whereas seawater contains over 35 ppt (SG = 1.0264) of salt per liter.
Therefore, technically, brackish water holds between 0.5 ppt (SG = 1.0004) and 35 ppt (SG = 1.0264) of salt per liter.
Important: As we can see the range of salinity in brackish water tanks is pretty huge and there are not many aquatic plants that can tolerate such fluctuations.
Therefore, in the aquarium hobby, when we are talking about brackish tanks we usually suppose that salinity ranges from 0.5 ppt (SG = 1.0004) to 10 ppt (SG = 1.0075).
Keep in mind that higher salinity levels have significant inhibitory effects on many aquatic plants that can tolerate brackish water. According to multiple studies and results of the experiments, that plant growth, regeneration, and colonization abilities decreased as salt concentration increased.
Popular Plants That Grow in Brackish Conditions include the following:
| Plants for Brackish Water | Optimal salinity levels | |
| 1. | Dwarf Water Lettuce (Pistia stratiotes) | up to 2.5 ppt (1.0019 SG) |
| 2. | Carolina Fanwort (Cabomba carolina) | up to 2.5 ppt (1.0019 SG) |
| 3. | Parrot Feather (Myriophyllum aquaticum) | Up to 3.3 ppt (1.0025) |
| 4. | Mexican Oak Leaf (Shinnersia rivularis) | up to 5 ppt (1.0038) |
| 5. | Dwarf Chain Sword (Helanthium tenellum) | up to 5 ppt (1.0038) |
| 6. | Vesicularia Dubyana | up to 5 ppt (1.0038) |
| 7. | Glossostigma elatinoides | up to 5 ppt (1.0038) |
| 8. | African Water Fern (Bolbitis heudelotii) | up to 5 ppt (1.0038) |
| 9. | African Tiger Lotus (Nymphaea zenkeri) | up to 5 ppt (1.0038) |
| 10. | Anubias (Anubias spp.) | up to 7 ppt (1.005 SG) |
| 11. | Cryptocoryne ciliata | up to 7 ppt or (1.005 SG) |
| 12. | Java fern (Microsorum pteropus) | up to 10 ppt (1.0075 SG) |
| 13. | Marimo moss balls (Aegagropila linnaei) | up to 6 ppt (1.0045 SG) |
| 14. | Brazilian micro sword (Lilaeopsis brasiliensis) | up to 7 ppt (1.005 SG) |
| 15. | Seaside Brookweed (Samolus valerandi) | up to 13 ppt (1.01 SG) |
| 16. | Water sprite (Ceratopteris thalictroides) | to 7 ppt (1.005 SG) |
| 17. | Aponogeton crispus | up to 7 ppt (1.005 SG) |
| 18. | Water spangles (Salvinia minima) | up to 7 ppt (1.005 SG) |
| 19. | Duckweed (Lemna minor) | up to 7-10 ppt (1.005 – 1.007SG) |
| 20. | Bacopa Caroliniana | up to 7 ppt (1.005 SG) |
| 21. | Guppy Grass (Najas guadalupensis) | up to 7 ppt (1.005 SG) |
| 22. | Cryptocoryne wendtii | up to 7 ppt (1.005 SG) |
| 23. | Bacopa Monnieri | up to 7 ppt (1.005 SG) |
| 24. | Hornwort (Ceratophyllum demersum) | up to 7 ppt (1.005 SG) |
| 25. | Anacharis (Egeria densa) | up to 8 ppt (1.006 SG) |
| 26. | Vallisneria sp.(Americana and spiralis) | up to 9 ppt (1.0068 SG) |
| 27. | Dwarf Sagittaria (Sagittaria subulata) | up to 10 ppt (1.0075 SG) |
| 28. | Sea grass (Zostera marina) | up to 25 ppt (1.0188 SG) |
| 29. | Sea lettuce (Ulva lactuca) | up to 25 ppt (1.0188 SG) |
| 30. | Widgeon Grass (Ruppia maritima) | up to 35 ppt |
| 31. | Red Mangrove (Rhizophora mangle) | up to 35 ppt (1.0264 SG) |
Before I start, I need to point out that without long acclimatization many freshwater aquatic plants are adversely affected by salt stress and increased salinity concentrations. Therefore, be patient. It may take days and even weeks before the plant will be absolutely ready.
1. Anacharis (Egeria densa)
Egeria densa or Anacharis is a popular aquarium favorite because of its attractive growth, versatility, and adaptability to varying water conditions.
Although a notable choice for mostly freshwater aquaria, this species can tolerate a bit of salinity hence it can be introduced into a low-end brackish aquarium.
According to the study, Anacharis was able to tolerate salt levels of up to 8 ppt (SG = 1.006) in laboratory conditions
This plant has a lush appearance that stands out, owing to its light green to bright green, finely serrated, narrowly lanceolate, sessile leaves, and long green brittle stems.
Anacharis grows well in warm, soft to hard water, with medium to high lighting conditions, whether planted in aquarium gravel or allowed to float on the water surface.
It will thrive in brackish tanks without CO2 and nutrient supplementation, and it does a good job of decorating the tank, removing excess nutrients, outcompeting nuisance algae, and oxygenating the tank water.
Anacharis Optimal Requirements:
- Water pH: 6.0 – 8.0
- Hardness: Soft to hard water
- Temperature: between the range of 20 – 24 °C (68 – 75 °F)
- Lighting: Medium to high lighting.
Care level: Easy.
For more information, read the article “Anacharis Care Guide – Planting, Growing, and Propagation”.
2. Anubias spp.
Native to the rivers, streams, and shady parts of marshes in tropical Western Africa where it grows partially or fully submersed, Anubias comprises many sturdy aquatic and semi-aquatic flowering plants which are well utilized in aquascaping freshwater and brackish aquariums, paludariums, and terrariums.
They will make excellent additions to brackish tanks due to their resilience, ease of care, and adaptability to a wide range of water chemistry values and lighting conditions.
Anubias has a tolerance for low salinity levels up to 1.005 sg (7 ppt) provided that the hobbyist slowly acclimates the plant to the brackish conditions.
Note: In rare cases, some Anubias can tolerate salinity levels up to 1.008 (10 ppt) but it will be their threshold.
Anubias barteri and Anubias congenis are fit for mid-ground or background usage in aquariums, whereas Anubias nana is suited for the foreground because of its small size, approximately 2 – 4 inches (5 – 10 cm). These plants are quite popular and readily available.
The plant is known for its lush, durable, and leathery green leaves, strong root structure, slow growth, and low demands. Anubias can be cultivated by placing the rhizome into the substrate (for mid-sized to large varieties), while small varieties like Anubias nana should be attached to rock or driftwood using a quality Cyanoacrylate glue or fine fishing line.
Lastly, Anubias will appreciate low – medium lighting, soft to moderately hard water, and an optimum temperature of 22 – 28 °C.
Anubias Optimal Requirements:
These plants are also very adaptable and can grow within a wide range of parameters.
- Water pH: 6.0 – 8.0.
- Hardness: Soft to hard water.
- Temperature: 72 – 82 °F (22 – 28 °C)
- Lighting: Low to medium
Care level: Easy.
For more information, read the article “Anubias Care Guide – Planting, Growing and Propagation”.
| Anubias – check out the price on Amazon |
3. Cryptocoryne (Cryptocoryne ciliata)
This is another ideal plant for brackish aquaria.
Cryptocoryne ciliata is one of the largest species in the genus Cryptocoryne, and it is widespread in the tidal zones and mangroves of South East Asia. Due to the nature of its habitat, the species can equally grow and thrive in a well-maintained brackish water tank with salinity levels up to 7 ppt or 1.005 sg.
Cryptocoryne ciliata is usually planted in the background areas of an aquarium because of its potential size despite the slow growth habit it exhibits. The plant is characterized by its large size; growing up to nearly 1 meter tall (3 ft.).
Also present are bright green, lanceolate to ovate, long-stalked fleshy leaves, and a spathe limb with many red-purple cilia along the margin.
For best growth, cultivate Cryptocoryne ciliata in a nutrient-rich substrate; not in sand or gravel substrates but in laterite-enriched substrates. This species has high lighting needs, and thus; be sure to provide ample lighting using a high-quality LED light in order to support the plant’s growth properly. Lastly, ensure to prune the shoots regularly to prevent the plant from overcrowding the brackish tank.
Cryptocoryne ciliata Optimal Requirements:
- Water pH: 6.0 – 8.0.
- Hardness: Soft to hard water.
- Temperature: 73 – 82 °F (23 – 28 °C)
- Lighting: High
Care level: Moderate.
4. Java Fern (Microsorum pteropus)
Java fern is one of the best aquatic plants in the hobby. The species is relatively hardy and easy to grow and it is well-adapted for life in both freshwater and brackish habitats.
This slow-growing, the plant grows fully or partially submerged in tropical rainforests, coastal brackish regions, and banks of freshwater streams and rivers.
Java fern will definitely survive in low-end brackish tanks with salinity up to 7 ppt or 1.005 sg and even higher (up to 10 ppt (1.0075 SG)), but not all specimens can cope with higher specific gravity comfortably.
Nonetheless, make sure to slowly acclimate the plant to brackish conditions rather than just throwing it directly into an established brackish aquarium. Furthermore, being an epiphytic species, the plant grows when fastened to hardscape like driftwood and rocks using adhesives or fishing wire.
Java fern Optimal Requirements:
- Water pH: 6.0 – 8.0.
- Hardness: Soft to hard water.
- Temperature: 20 – 28 C (68 – 82 F)
- Lighting: Low to Moderate lighting.
Care level: Easy
For more information, read the article “Java Fern Care Guide – Planting, Growing and Propagation”.
| Java Fern – check out the price on Amazon |
5. Marimo Moss Ball (Aegagropila linnaei)
Marimo moss ball or Cladophora ball is a type of green algae which is commonly used in tropical aquariums.
These slow-growing, filamentous green algae live predominantly in lakes in the northern hemisphere, and it can also be found in cool freshwater and brackish habitats with salinity up to 1.0045 SG or 6 ppt.
It is worth noting that Marimo moss balls require a cool temperature for optimal health, and when the water temperature exceeds 24 °C the balls will start to fall apart.
Marimo is hardy and undemanding, and it is capable of tolerating a wide range of water parameters provided that the values are not rapidly-changing.
These green spherical algae balls can reach 8 to 12 inches (20 – 30 cm) in diameter in their natural habitat. However, the commercially available versions are sold at 2 inches (5 cm) or smaller. Although rare, Marimo moss balls don’t cost much to obtain.
Marimo Moss Balls Optimal Requirements:
- Water pH: 7.0 – 8.0.
- Hardness: Soft to hard water.
- Temperature: 5 – 24 °C (43 – 75 °F)
- Lighting: Low to Moderate lighting.
Care level: Easy.
| Marimo Moss Balls – check out the price on Amazon |
6. Brazilian Micro Sword (Lilaeopsis brasiliensis)
Brazilian micro sword is equally a worthy candidate for brackish tanks since the species can tolerate slightly brackish water, up to 7 ppt or 1.005 sg with no difficulty.
Notably, this plant forms a beautiful thick carpet under very intensive light conditions, CO2, and nutrient supplementation.
Lilaeopsis brasiliensis is a popular carpet plant that has a grasslike appearance owing to its flat sword-like leaves.
The species is noted for its great carpeting ability, tolerance, hardiness, and versatility, and thus; Brazilian micro sword is often used in nano, mid-sized and large aquariums for aquascaping the foregrounds and midgrounds due to the lush green tufts it produces.
Also, the carpet plant requires a nutrient-rich substrate e.g. iron-rich clay soil or aquarium soil plus high lighting and CO2 to grow vigorously in both freshwater and brackish aquarium setups.
Brazilian Micro Sword Optimal Requirements:
- Water pH: 6.0 – 8.0.
- Hardness: Soft to very hard water.
- Temperature: 18 – 25 °C (64 – 77 °F)
- Lighting: Moderate to high lighting
Care level: Easy – Medium
7. Seaside Brookweed (Samolus valerandi)
Seaside brookweed is a perennial flowering plant that grows in a variety of habitats such as tidal marshes, seeps, and banks of streams and rivers.
Seaside brookweed is suitable for accenting the foregrounds of freshwater and brackish water tanks, and it is also an interesting flora for the paludarium.
This amphibious plant has small, pale green obovate to spatulate leaves arranged in a rosette, and white flowers borne on long stalks. The size of Seaside brookweed varies depending on growth conditions, generally, the plant’s height can reach 15 cm (6 inches) when grown underwater.
Brookweed is one of the few species that can tolerate considerable levels of salinity up to 13 ppt or 1.01 sg. However, the downside of this species is that it is sometimes incapable of surviving extremely long periods fully submersed regardless of how ideal the water chemistry is, so keep that in mind before purchasing the plant for your brackish aquarium.
Additionally, Brookweed needs abundant high lighting, cool temperatures, fertile loamy or clay soil, as well as regular nutrient supplementation to thrive.
Brookweed Optimal Requirements:
- Water pH: 6.0 – 8.0.
- Hardness: Soft to moderate water.
- Temperature: 18 – 25 °C (64 – 77 °F)
- Lighting: Moderate to high lighting
Care level: Easy – Medium
8. Water Sprite (Ceratopteris thalictroides)
A floating aquatic fern prized for its lush green appearance, minimal maintenance, and easy care.
Water sprite is a versatile plant that can be grown either emersed or submersed, rooted in the substrate, or floated in the water column. This species will tolerate low levels of salinity up to 1.005 sg (7 ppt), however, it needs to be acclimated over a few days else it may not thrive.
In addition, it prefers medium – high lighting and water temperature above 20 °C to grow well in the tank.
Water sprite has vibrant light green, feathery foliage, and a branched leaf structure that will surely transform the look of your brackish aquarium.
Water sprite Optimal Requirements:
- Water pH: 6.5 – 0
- Hardness: Soft to hard water
- Temperature: 22 – 27 °C (70– 82 °F)
- Lighting: Moderate to high lighting
Care level: Easy
| Water Sprite – check out the price on Amazon |
9. Water spangles (Salvinia minima)
Water spangles is a free-floating plant that grows rapidly on the water surface of warm, stagnant, or slow-moving freshwater bodies such as ponds, streams, lakes, canals, swamps, wetlands, and brackish marshes.
Water spangles can be a good choice for brackish tanks; the plant can tolerate low salinity levels between 4 to 7 ppt (1.003 – 1.005 SG).
This plant grows fast and does well with little or no fertilization at all in heavily stocked aquariums.
Water spangles Optimal Requirements:
- Water pH: 0 – 8.0
- Hardness: Soft to hard water
- Temperature: 22 – 26 °C (72– 79°F)
- Lighting: Moderate to high lighting
Care level: Easy
10. Vallisneria (Vallisneria sp.)
Vallisneria sp. has been an aquarium hobby since forever. This is probably one of the most common and versatile plants, most fish stores have some sort of variation of this plant.
This fast-growing and undemanding plant can grow in any kind of substrate. Depending on the tank setup, Vallisneria sp. can get nutrition from the substrate and/or from the water column.
According to some experiments, Vallisneria sp. can tolerate up to 15 ppt (1.0113 SG) for many weeks. At salinities 9 ppt (1.0068 SG), growth was greater during the wet season than during the dry season.
Vallisneria sp. Optimal Requirements:
- Water pH: 6.5 – 8.0
- Hardness: Soft to moderately hard water.
- Temperature: 20 – 28 °C (68 – 82 °F)
- Lighting: Moderate
Care level: Easy
For more information, read my article “Vallisneria Care Guide – Planting, Growing, and Propagation”.
| Vallisneria – check out the price on Amazon |
11. Duckweed (Lemna Minor)
Duckweed is probably the most controversial plant in the aquarium hobby. It is either you love it or hate it there is no in-between.
These plants can double their total biomass every 2 to 4 days. Basically, they are one of the plants with the most vigorous growth on the earth.
Duckweed is extremely hardy and capable of tolerating a huge range of water parameters. It makes Duckweed an ideal candidate for different kinds of tank setups including brackish tanks.
Duckweeds are salinity tolerant, it can adapt with time to high salinity. Results of the experiments showed that salinities of 16.6 ppt (1.0125) or higher were toxic to Lemna minor.
According to another study, duckweed is also an efficient natural biofilter in both brackish and freshwater closed systems. Even more salinity up to 7 ppt (1.0053 SG) even enhances ammonium uptake
Duckweed Optimal Requirements:
- Water pH: 6.5 – 7.5
- Hardness: Soft to moderately hard water (2 – 15 GH).
- Temperature: 60 – 85 degrees Fahrenheit (15 – 30C).
- Lighting: Moderate – high lighting.
Care level: Easy
Read more about it in the article Duckweed Care Guide – Planting, Growing, and Propagation”.
| Duckweed – check out the price on Amazon |
12. Bacopa Caroliniana
Bacopa Caroliniana is another exceptionally undemanding plant species that are suitable for any kind of tank setup. A simple fact that it can grow equally well even in freshwater and brackish water (salinity up to 1.005 sg (7 ppt)) should tell you how hardy it is.
Bacopa Caroliniana is a classical aquarium plant that is ideal for adding vertical accents in the background of aquariums.
These beautiful plants will offer a great contrast to any other plants in the aquarium. It also produces a lemon-mint smell at the place of cut.
One of the reasons for its popularity is because this is a very easy and beginner-friendly plant.
Bacopa Caroliniana Optimal Requirements:
- Water pH: 6.0 – 8.0.
- Hardness: Soft to hard water.
- Temperature: 68 – 78 °F (20 – 26 °C)
- Lighting: Low to high lighting.
Care level: Easy.
13. Dwarf Water Lettuce (Pistia stratiotes)
Dwarf Water Lettuce or Water cabbage is a floating plant adored by many aquarists because of its fast-growing ability and undemanding nature.
According to the study, Pistia stratiotes has a low saline tolerance. It can survive in waters only up to 2.5 ppt (1.0019 SG) salinity.
This species is native to the Amazon and is widely distributed across the globe where it spreads like a weed – especially in subtropical and tropical regions.
Besides being beautiful in your aquarium, Water Lettuce is great for removing and sucking up nitrates, ammonia, heavy metals, and sediments from the water.
As a floating plant, there is no need for CO2 supplementation. Also, you do not have to fertilize it unless the water is very low in nitrates or you really want to cultivate them.
Its long root system is a habitat for aquatic animals such as young fishes, and dwarf shrimp.
Dwarf Water Lettuce Optimal Requirements:
- Water pH: 6.0 – 7.5
- Hardness: Soft – medium
- Temperature: 22 – 28 °C (71 to 82 °F)
- Lighting: Moderate to high lighting
Care level: Easy
| Dwarf water lettuce – check out the price on Amazon |
14. Dwarf Sagittaria (Sagittaria subulata)
In nature, Dwarf Sagittaria can be seen growing in marshes, estuaries, and shallow waters (freshwater and brackish) in emersed, and submersed form.
According to the Classification of the Natural Communities of Massachusetts, Sagittaria subulata was listed amongst other plants that often occur along the edges of salt marsh habitat with average annual salinity around 5-18 ppt (1.0038 – 1.0135 SG).
Nonetheless, for the best results, it is better to have salinity up to 10 ppt (1.0075 SG.)
Dwarf Sagittaria Optimal Requirements:
- Water pH: 6.0 – 8.0.
- Hardness: Soft to hard water
- Temperature: 20 – 28 °C (68 – 82 °F)
- Lighting: Low to Moderate lighting
Care level: Easy
15. Guppy Grass (Najas guadalupensis)
Guppy grass grows primarily in freshwater to brackish tidal Bay tributaries. It can be kept in low salinity brackish tanks with up to 7 ppt (1.005 SG).
This plant is very easy to grow. Thus, it is great both for a beginner’s and a pro’s aquarium.
Guppy grass does not demand much attention and can be floated or rooted in the substrate.
Guppy Grass Optimal Requirements:
- Water pH: 6.0 – 8.0.
- Hardness: Soft to hard water.
- Temperature: 20 – 26 °C (68 – 79 °F)
- Lighting: Low to Moderate lighting.
Care level: Easy
For more information, read the article “Guppy Grass Care Guide – Planting, Growing and Propagation”.
In Conclusion
In general, most freshwater aquarium plants do not tolerate increasing salt concentration.
Even more, as we can see in my list of brackish water plants, some species can tolerate only low or intermediate levels of salinity while broadly adapted species can acclimate to high salinity levels.
Don’t forget that you cannot simply just take a plant from freshwater and drop it in brackish water. Even the most salt-tolerant plant may not survive if you do that.
The transition from freshwater to brackish water must be gradual. In some cases, it can take weeks!
Great info. My personal experience is that lemon bacopa does well only in low salinity (3ppt), along with water cabbage, african tiger lotus, and water spangles. Toughest (with changing salinity from 5-10ppt and temps from 68-92F) was valisneria, anubias, java fern, micro sword, java moss, guppy grass, hornwort, and wisteria. Emergent vegetation in my setup (2000gal outdoor, heated, green housed during Florida winter, pond) include mangroves (black, white, red, oriental), crinum, purple flag iris, giant leather fern, variegated pandanus and will be adding golden leather fern.
Hi Bruce,
Thanks for your feedback!
When I was writing the article, I took those numbers from different scholarly publications.
It is quite probable that the tolerance will also depend on other environmental characteristics such as (photoperiod, light intensity, temperature, etc.). Therefore, under optimal conditions, its tolerance might be higher.
Best regards,
Michael