Bacopa caroliniana is an exceptionally undemanding plant species that is suitable for any kind of tank setups. It is one of the oldest and most renowned plants in the aquarium hobby; touted for its sturdy structure, easy-care, adaptability, and tolerance.
Keep reading for everything you need to know about Bacopa caroliniana, and how to grow it in your aquarium.
Quick Notes about Bacopa Caroliniana
|Common Name||Bacopa Carolinaina|
|Other Names||Lemon bacopa, Blue waterhyssop, Mint bacopa|
|Optimal pH||6.0 – 8.0|
|Optimal GH||Soft to hard|
|Optimal Temperature||20 – 28 °C (68 – 82 °F)|
|Placement in Tank
|Size||20 to 40+ cm (8 – 16 inches or more)|
||Not needed to low|
|CO2||Not needed to low|
||Green to reddish|
Origin of Bacopa Caroliniana
Bacopa caroliniana is native to North America, it is a species of the genus Bacopa which consists of about 70 – 100 aquatic plants belonging to the family Scrophulariaceae.
Let’s take a brief look at the taxonomical hierarchy of Bacopa caroliniana.
Kingdom: Plantae (The plant kingdom).
Clade: Tracheophytes (Vascular plants).
Clade: Angiosperms (Flowering plants, also known as Magnoliophyta).
Order: Lamiales (An order of dicotyledonous flowering plants).
Family: Scrophulariaceae (A family of flowering plants, commonly known as the figwort family).
Genus: Bacopa (Waterhyssop)
Species: Bacopa caroliniana
Common names: Lemon bacopa, blue waterhyssop, mint bacopa.
Synonyms: Bacopa amplexicaulis, Obolaria caroliniana, Herpestes amplexicaulis, Herpestes caroliniana.
Habitat of Bacopa Caroliniana
Bacopa caroliniana is commonly seen in Florida, and it is also widely distributed throughout the Southeastern United States. Huge populations of blue waterhyssop have been reported in Texas, South Carolina, Alabama, Maryland, etc.
Bacopa caroliniana is a hydrophyte, hence its occurrence in wetlands, marshes, lakes, and ponds where it grows as a submersed or emergent plant. This plant is great for paludarium set ups.
Description of Bacopa Caroliniana
Bacopa Caroliniana is a perennial stem plant that can grow in two forms (emersed and submersed). In its emersed form, the stems are about 2.5mm to 5mm thick, sparsely pilose, up to 1 meter long (3 ft), prostrate, and rooting at the nodes.
The leaves are opposite (individual pairs arranged crosswise as well, their bases clasping the stem), fleshy and succulent, ovate or elliptical, 20 to 30 mm (~1 inch) long, and 10 to 15 mm (~0.5 inches) wide.
The upper surface of the leaves is glossy green, the lower surface finely pubescent, and flowers are bright blue in color. When the leaves of this plant are crushed, it will emit a strong scent similar to that of lemon or mint.
The submersed form of this plant is characterized by an average size of 20 – 40 cm (8 – 16 inches) long, 3 – 4 cm (1 – 1.5 inches) wide, green or greenish yellow leaves with darker, clearly discernable veins that are moderately undulate.
Under intense lighting condition in addition to low nitrate levels, the shoots will gain a bronze or copper-brown, and sometimes pink coloration. Bacopa caroliniana is an attractive plant species, and its rare variant “Colorata” is even better as it has a more pronounced light red coloration.
Bacopa caroliniana has a slow growth rate compared to most aquatic plants, and this makes its care even easier. The plant requires strong lighting to attain its bright colors, although it will equally thrive in low light conditions, CO2 injection is essential but not mandatory.
Tank Requirements and Water Paremeters
Bacopa caroliniana will reward you with a healthy and robust growth if appropriate water parameters are maintained, and nutritional requirements are adequately met.
Although this plant species can thrive in a variety of tank sizes (even suited for nano tanks if properly maintained).
However, because of the large nature and mass of this plant species, the minimum tank size for growing Bacopa caroliniana is 10 gallons (~40 L). After all, this is a pretty tall plant.
Water type, Temperature, Hardness, and pH:
Temperature: Optimal temperature for growing Bacopa caroliniana is between the range of 20 – 28 C (68 – 82 F), Bacopa caroliniana is tolerant of cooler temperatures as well (not lesser than 13 °C).
pH: The recommended pH range for the species is 6.0 – 8.0, this is best for the plant. Nonetheless, the plant can easily adapt to almost any pH as long as extremes are avoided.
Hardness: Bacopa caroliniana can tolerate hard and soft water equally. Nonetheless, it will thrive best in water hardness between the ranges of 2 – 15 GH.
Bacopa caroliniana will grow in fairly low light levels to high lighting levels, that is why it is one of the best plants for low light planted tanks. Personally, I believe that this is the best plant because of how adaptive it is.
However, strong lighting will provide the best growth. In addition, the top leaves will turn reddish under sufficient bright light. If the plant is exposed to low lighting it will grow just green.
You will be doing this plant a huge favor by maintaining a photoperiod of 8 – 10 hours on a daily basis.
Bacopa caroliniana does not require a nutrient-rich substrate. Although it will benefit the plant. This plant can grow in sand or gravel. As long as your fish and snails produce enough bioload (waste), you do not even need to add any fertilizers.
CO2 and fertilization:
Bacopa caroliniana will thrive without CO2 injection.
Fertilizer application depends on the tank setup. For example, if your substrate is rich with minerals or there is a lot of fish and snails waste in the tank, it can be enough.
Tip: In most cases, stem plants feed from the water column. That is why if you decide to use one, you should dose liquid fertilizers. Root tabs will not be that effective.
In other cases, the plant may not perform too well in tanks without fertilizer application. So, you will have to add some from time to time to maintain a normal growth rate and overall good health.
Iron and potassium supplements will help it maintain its appealing green coloration and healthy leaf structure.
Important: If you keep shrimp in the tank with the Bacopa caroliniana, I would highly recommend reading my articles:
CO2 in a Planted Tank Guide
CO2 in a Shrimp Tank
How Copper Affects Dwarf Shrimp
Shrimp Safe Plant Fertilizers
The point is that a high level of CO2 and Copper (most fertilizers contain copper) is extremely dangerous to the shrimp.
Care and Maintenance of Bacopa Caroliniana
If left alone, the plant will produce long and robust stems that will reward the hobbyist with strong vertical accents in the aquarium. A major twist is that regular pruning contributes positively to the development and propagation of lemon bacopa.
Regular pruning of the top or lateral shoots aids the proliferation of numerous side shoots which results in a thick and bushy look / effect after a while.
Cuttings can either be replanted or properly disposed in waste bags to prevent them from getting into local waterways. You can equally dip the detached stems in a bleach solution to kill them off before disposal.
Endeavor to perform weekly partial water changes, and clean up / remove dead leaves, flowers, and stems to maintain good water quality.
When there is an abudance of CO2, bright lighting, and essential nutrients in the tank water, the plant will surely respond positively to it. This will be exhibited by a slightly faster growth, an intense coloration, and thicker leaves.
Note: Bacopa caroliniana often starts out slow but once established, it will grow faster.
Planting and Propagation of Bacopa Caroliniana
Bacopa caroliniana can be cultivated by placing healthy specimens into the substrate with pincette, be careful not to break the fragile stems while doing this. At the early stages, the plants will appreciate the addition of fertilizers as it promotes healthy growth and overall development.
Propagating Bacopa caroliniana is easy, the lateral shoots (coming out of the stalk at the nodes) can be cut off and replanted in the substrate.
Ideally, these cuttings should be 3 – 6 inches (7 – 15 cm) long, remove the leaves from the lower 2 inches (bottom) of the stem and place it into the substrate. The side shoots produced by this plant can also be clipped and replanted, it will root after some days to form a new plant.
Do not plant stems to close to each other. Overcrowding will cause higher competition for nutrients which will affect the health of the plants.
Note: Sometimes aquarists let Bacopa caroliniana float after trimming until they develop some roots.
Benefits and Uses of Bacopa Caroliniana
Aquascape: Bacopa caroliniana is a very tall plant. Therefore, it can be used to decorate the background sections of an aquarium. Its bold tall structure, bright hues, and uniformed leaf patterns accentuates the aesthetic appeal of tanks, thereby making it a delight for viewers.
Foraging place: Bacopa caroliniana serves a foraging ground for fish, shrimp, and snails, they will be seen scavenging on the stems or base for tiny food particles and detritus. In addition, this plant will be an additional place for the growth of biofilm, which is an ideal first food for newly hatched fry and shrimplets.
Removal of excess nutrients: Lemon bacopa is known to utilize excess nutrients, as well as heavy metals, therefore, purifying the tank water.
Shelter: Shrimp and small fish species use this plant as a cover and breeding place to lay their eggs on.
Oxygenation: Helps in oxygenating the water column.
Reduces algal bloom: Bacopa caroliniana helps in reducing the overall probability of algal bloom in the given environment. The plant is pretty greedy for nutrients. So, it simply outcompetes algae.
Source of Food: Bacopa carolinaina and Bacopa monnieri are considered edible and can be used to make salads.
Interesting fact: According to studies, Bacopa carolinaina and Bacopa monnieri can be used for medicinal purposes: treating rheumatism, oral infections, long congestion, psychosis, and lots more.
Problems Associated with Bacopa Caroliniana
Melting: Sometimes you may witness Bacopa carolinaina melting in the tank, this might be due to poor water quality, or in cases where the plant was grown out of water and has not acclimated.
All you need to do is to get rid of the dying parts, monitor the water quality to ensure it is in a good condition, and dose fertilizers to enable the plants bounce back to normal health.
Algae: Algae growth can be as a result of the introduction of infected plants and aquarium materials. In addition, it can be due to poor water quality and excessive lighting conditions which could trigger the growth of algae.
This can be curtailed by fixing the water quality, reducing the light intensity and photoperiod, also by disinfecting plants and aquascaping materials before placing them in the tank.
Difficulty in staying rooted: Another common problem is the inability of the plant’s stems to stand firm in the substrate without floating up. At this juncture, one can employ plant weights to hold down the stems; they are thin, flexible, non-toxic, and easy to wrap around the stems before placing them back into the substrate.
Loss of lower leaves: The bottom of Bacopa carolinaina often starts to look ratty because the leaves at the top get much bigger and block out the light. If you have noticed the degradation of the lower part in Bacopa carolinaina, it is recommended to cut the lower part of the plant and replant the upper part.
Bacopa Caroliniana vs Bacopa Monnieri
Both are common species of the genus Bacopa, they have varying features that distinguish them from each other.
- Bacopa caroliniana has blue flowers and round, aromatic leaves whereas Bacopa monnieri (waterhyssop) is characterized by white flowers and unscented leaves that are broader at the tip than at the base.
- The leaves of Bacopa caroliniana are also bigger in general.
- Bacopa caroliniana has a darker stem, where Bacopa monnieri has just all green stem.
- If we compare the stems of these plants we will see that Bacopa monnieri’s stems are more straight compared to Bacopa caroliniana which are a little bit twisted.
Note: Both species possess medicinal qualities, and can be used to treat lots of ailment.
Bacopa Caroliniana and Tankmates
Bacopa carolinaina is sturdy, and can be introduced to any kind of freshwater tanks, with less worries over fish eating it. According to observations, there are lower chances of bacopa being eaten by fish species, even those known to nibble on leaves are likely to shy away from this plant.
This may be due to the scent of the leaves which is unpleasant to fish species. Even when some make attempts to eat it, the plant is strong enough to survive their attacks.
If you are still skeptical and prefer to play safe, you can go for livebearers, shrimp, and snails. For example:
- Peaceful Fish. It would be a nice idea to keep this plant in the company of fish that won’t harm it. Good examples include Otocinclus Catfish, Pygmy Cory Catfish, Neon Tetras, Guppy, Cherry Barb, Green Swordtails, Rasboras, Red, or blue wagtail platy, etc.
- Shrimp. In addition, shrimp species – all varieties of Neocaridina species (Red Cherry Shrimp, Blue Velvet Shrimp, Black Rose, Snowball shrimp, Orange Sakura, Green Jade, Rili Shrimp, etc) or Caridina species (for example, Crystal Red Shrimp, Caridina cf. babaulti, Blue Tiger Shrimp, etc.), Amano shrimp, Ghost shrimp, Bamboo shrimp, Vampire shrimp, Basically, you can keep any shrimp species with it. They will love it!
- Snails (for example, Ramshorn snails, Nerite snails, Malaysian Trumpet snails, Japanese trapdoor snails, Mystery snails,). Be careful with snails that can harm or try to devour the plant. Check out the list of freshwater snails here.
Do not keep Bacopa carolinaina with crayfish or crabs. It is a well-known fact that these invertebrates are plant destructive (read my introduction to crayfish care). Even if they will not eat Bacopa Carolinians, they can still cut or uproot the plant in the tank. Therefore, the best choice will be to have floater plants in their tanks.
Buying Bacopa Caroliniana
This plant can be obtained from a variety of sources- local aquarium/pet stores, water garden supply shops, nurseries that sell aquatic plants as well as reputable vendors on the internet.
A single pot or bunch can come with up to 10 stems, your duty at this point is to make sure that the plants are in a good condition: devoid of visible damages (rips, curls, and rot), pests and algae. You wouldn’t want to introduce a sick or disease-ridden plant to your aquarium, so be cautious!
Quarantine Bacopa Caroliniana
Unless you are completely sure that Bacopa carolinaina is safe, for example, it was grown in sterile/laboratory conditions (in vitro) and in vitro pot is not damaged or opened, do not forget to quarantine and disinfect it first to avoid the risk of contamination and poisoning.
DO NOT introduce a new plant to your tank right after you bought it.
- The plant can have parasites, pests like snails, or even predators (dragonfly, damsefly nymphs, etc.).
- It may already contain residues of chemicals (pesticide) to remove parasites, snails, etc. These chemicals are extremely poisonous to fish, shrimp, and other invertebrates.
To find out more, read my articles:
Bacopa carolinaina is easy to grow and requires minimal care, this makes it an excellent choice for beginners. Lemon bacopa will survive in freshwater with varying degrees of temperature and hardness conditions, even in brackish water too.
This plant species will create strong vertical accents in the background of tanks with its thick long stems, and that’s just one of the numerous benefits it brings to planted tanks.
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