How do you grow Hydrocotyle tripartita in an aquarium? Plant small portions in the foreground or midground, give medium to high light and trim it often. Tropica says Hydrocotyle tripartita ‘Japan’ forms a compact carpet 2 to 4 inches (5 to 10 cm) tall in good light. Dennerle lists 64 to 82°F (18 to 28°C), pH 5 to 8 and soft to hard water.
Key takeaway: Hydrocotyle tripartita, often sold as Hydrocotyle sp. ‘Japan’, is a fast, clover-leaved pennywort that carpets in good light. Tropica rates its light need medium and CO2 need low, and says pressing the carpet by hand keeps growth compact. Dennerle lists higher light, 20–30 mg/L CO2, 64–82°F (18–28°C) and pH 5–8. Trim runners often or it will climb over neighbors.
| Fact | What sources report | Source |
|---|---|---|
| Family | Apiaceae (pennywort) | Dennerle |
| Origin | Southeast Asia variant (Tropica); Australia (Dennerle) | Tropica, Dennerle |
| Height | 2–4 in (5–10 cm) carpet; up to about 8 in (20 cm) | Tropica, Dennerle |
| Light | Medium (Tropica); high–medium (Dennerle) | Tropica, Dennerle |
| CO2 | Low (Tropica); 20–30 mg/L (Dennerle) | Tropica, Dennerle |
| Temperature and pH | 64–82°F (18–28°C); pH 5–8 | Dennerle |
| Growth and propagation | Fast; head cuttings | Dennerle |
What Is Hydrocotyle Tripartita?
Hydrocotyle tripartita is a small water pennywort in the carrot family, Apiaceae. Tropica says the plant called Hydrocotyle sp. ‘Japan’ in forums is a variant of it from Southeast Asia, with fast, compact growth and small, intense green leaves on vertical stems. Dennerle lists the origin as Australia and notes its species identity is not yet certain.
Its leaves are tiny and clover-shaped, which makes it easy to tell apart from the larger round leaves of Brazilian pennywort. It creeps by runners and can carpet, climb rocks or spill over other plants.
- Look: three-lobed, clover-like leaves under 1/2 inch (1 cm).
- Use: foreground carpet, midground bush or rock cover.
- Growth: fast, so it needs frequent trimming.
How Do You Grow Hydrocotyle Tripartita in an Aquarium?
Split the pot or tissue-culture cup into small clumps and plant them a few inches apart. Tropica says this pennywort is carpet-forming and that compact growth can be promoted by pressing the carpet down with your hand during maintenance. Dennerle adds that under strong light it creeps across the substrate and even across other plants.
- Rinse off rock wool or gel and divide into small portions.
- Push each portion into fine substrate with tweezers.
- Space clumps about 1–2 inches (2.5–5 cm) apart.
- Give medium to high light from day one.
- Press runners down and trim them as they spread.
For a smoother carpet you can pair it with Monte Carlo or dwarf hairgrass, though the pennywort will grow over slower plants if left alone.
What Light Does Hydrocotyle Tripartita Need?
Medium light works, and brighter light gives a tighter carpet. Tropica rates its light demand as medium, about 0.5 W/L, and says carpet formation and compact growth do best in good light. Dennerle rates it high to medium. In low light it grows taller and stemmy instead of spreading flat.
Run lights 7 to 8 hours a day. If stems stretch and gaps open between leaves, raise light intensity or lower the light fixture before you add more fertilizer.
Does Hydrocotyle Tripartita Need CO2 and Fertilizer?
CO2 helps but is not essential. Tropica rates its CO2 need as low, while Dennerle lists 20 to 30 mg/L, the range many high-tech tanks run. Without CO2 it still grows, but more loosely. As a fast grower it uses nutrients quickly, so dose a complete liquid fertilizer and add root tabs in inert substrates.
Pale new leaves often point to low nitrogen or iron. See our guides to aquarium CO2 for plants, aquarium plant fertilizer and aquarium root tabs.
- CO2: low need (Tropica); 20–30 mg/L ideal (Dennerle).
- Fertilizer: regular liquid dosing.
- Substrate: nutrient-rich soil or root tabs.
What Water Parameters Does Hydrocotyle Tripartita Like?
It is not fussy. Dennerle says the plant is not demanding about water conditions and lists 64 to 82°F (18 to 28°C), pH 5 to 8 and soft to hard water. That fits most community and shrimp tanks. Keep parameters stable, and focus on light and nutrients, which shape its growth far more than pH does.
- Temperature: 64–82°F (18–28°C).
- pH: 5–8.
- Hardness: soft to hard.
- Flow: gentle flow keeps the carpet clean.
How Do You Trim and Propagate Hydrocotyle Tripartita?
Trim it often and replant the clippings. Dennerle lists head cuttings as the propagation method and advises removing overgrowth with scissors or a knife now and then. Tropica’s tip of pressing the carpet by hand also keeps it compact. Each trimmed runner with a few leaves can root as a new plant.
- Cut runners that climb over other plants or hardscape.
- Trim the top of the carpet evenly when it gets taller.
- Replant healthy tips in bare patches.
- Remove all loose cuttings so they do not drift into filters.
Why Is Hydrocotyle Tripartita Melting or Not Growing?
Melting is often short-term after planting, especially with emersed-grown plants that drop old leaves underwater. Ongoing problems usually come from low light, poor nutrients or a thick carpet that shades its own base. Trim the carpet, check fertilizer and light, and replant healthy tips. New submerged leaves typically appear within a couple of weeks.
- Leggy stems: too little light.
- Yellow or pale leaves: low nutrients.
- Brown lower layer: carpet too thick; thin it.
- Algae on leaves: light too strong for the CO2 and nutrients.
For other fast-growing choices, see floating plants for aquariums.
FAQ About Hydrocotyle Tripartita
Is Hydrocotyle tripartita easy to grow?
Yes; Dennerle calls it undemanding in water conditions.
Does it need CO2?
Tropica rates the need low; CO2 makes it denser.
Is it the same as Hydrocotyle ‘Japan’?
Tropica says ‘Japan’ is a variant of Hydrocotyle tripartita.
How tall does it grow?
About 2–4 inches (5–10 cm) as a carpet.
How do you propagate it?
By head cuttings and replanting runners.
What temperature does it need?
64–82°F (18–28°C), per Dennerle.
Sources
- Tropica Aquarium Plants — Hydrocotyle tripartita plant info/4458)
- Dennerle Plants — Hydrocotyle tripartita plant profile/27876)
- Photo credits (Wikimedia Commons, edited with titles): Hydrocotyle tripartita habit1 (9005151481) by Harry Rose from South West Rocks, Australia (CC BY 2.0); Hydrocotyle tripartita by S.E. Thorpe (Public domain)