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Hydrocotyle Tripartita (Japan)

Hydrocotyle tripartita 'Japan'

Common names: Hydrocotyle Tripartita (Japan), Hydrocotyle tripartita

Foreground, Hardscape, MidgroundFast

Countries of origin

  • See all stock from Australia
  • See all stock from New Zealand

Good fit for your tank?

Good fit for

  • Fast green carpets, low bushes, and growth draped over hardscape
  • Shrimp aquariums with stable foreground conditions
  • Planted aquariums using fine substrate and controlled flow
  • Keepers willing to trim, thin runners, and replant lifted portions

Think carefully if

  • The aquarium is newly cycled or already struggling with algae
  • Fish regularly dig or disturb the substrate
  • CO₂, fertiliser, or lighting is inconsistent
  • Japan is an aquarium trade form. It can grow upward or climb over neighbouring plants when light is low or trimming is delayed.

A small foreground, runner, rosette, grass-like, or carpeting plant with small three-lobed leaves on creeping and branching stems. Best used for fast green carpets, low bushes, and growth draped over hardscape; planting depth and stability are important.

Growth and Appearance

Usual aquarium appearance

This small plant has small three-lobed leaves on creeping and branching stems. Its common colour is light to bright green. Leaf height, density, and colour can change with light, CO₂, nutrients, water depth, trimming, and the individual plant.

Branching stems can creep across substrate, climb hardscape, or grow upward.

It is normally used for fast green carpets, low bushes, and growth draped over hardscape. During the first few weeks, watch for firm crowns, fresh roots, runners, creeping tips, or new submerged leaves rather than expecting immediate coverage.

Requirements

Substrate
Use a fine substrate that can hold small roots and runners. root feeding species benefit from suitable substrate nutrition, while utricularia graminifolia does not require rich substrate.
Root feeder
Yes
Water-column feeder
Yes

Essentials

  • Start with low to medium light.
  • Use a fine planted substrate or inert fine gravel with suitable root nutrition.
  • Provide gentle circulation that does not uproot small portions.
  • Use a complete fertiliser carefully when the aquarium does not already provide enough nutrients.
  • Keep water conditions and temperature stable instead of chasing one exact number.
  • A recently cycled tank can work, but an established aquarium is easier.

Optional improvements

  • Stable injected CO₂ can improve rooting, runner production, density, and recovery.
  • Small planting portions spaced apart usually establish more evenly than one thick clump.
  • Regular gentle cleaning prevents debris from settling inside a carpet.

Beginner setup checklist

  • Cycled, filtered freshwater aquarium
  • Fine substrate suitable for small roots
  • Stable light schedule
  • Gentle water movement
  • Consistent fertilising
  • Fine planting tweezers and sharp scissors
  • Fish that will not dig or uproot the foreground

CO₂ guidance

Injected CO₂ is recommended for reliable compact or carpeting growth, but it is not automatically required. Stable CO₂ can improve runner production, rooting, density, leaf form, and recovery after planting or trimming.

Keep CO₂ steady and balance it with light, complete nutrition, circulation, and oxygen. Do not raise light sharply before the plant is producing healthy new growth.

Planting and Care

Growth rate
Fast
Growth form
Carpet, Creeping, Stem
Rooting type
Rooted
Propagation
Cutting, Runner
Emersed growth
Yes

Preparation

  • Remove pots, foam, metal bands, and rock wool.
  • Rinse the roots and remove fully damaged or decaying tissue.
  • For tissue culture, wash away all gel.
  • Divide the plant into small plugs or natural clumps.

Planting a carpet

  • Use fine tweezers to insert each plug shallowly into the substrate.
  • Keep healthy leaves and creeping tips above the substrate.
  • Space portions a few centimetres apart rather than planting one thick bunch.
  • Plant slightly deeper only when necessary to prevent lifting, without burying the whole plant.

Attachment is optional

This plant is normally rooted in substrate, but healthy creeping stems can be guided over porous stone or wood.

  • Use loose thread or a small amount of plant-safe gel glue on a bare stem section.
  • Do not glue leaves or crush the growing tips.
  • Trim regularly so the plant does not smother slower hardscape plants.

Carpet trimming

  • Use clean, sharp scissors and trim a thin upper layer after the plant is firmly rooted.
  • Remove loose cuttings immediately with a net or siphon.
  • Thin dense or lifted sections so the lower layer does not become shaded and decay.
  • Do not cut a newly planted or melting carpet heavily.
  • Healthy trimmings with nodes or roots may be replanted when appropriate.

Light, regular trimming encourages branching and keeps a carpet low. A very thick untrimmed mat may lift away from the substrate.

Propagation by cuttings, stolons, or divided plugs

  • Select a healthy rooted or actively growing section.
  • Cut or separate a small plug with leaves and nodes.
  • Plant it shallowly with the growing tips exposed.
  • Keep flow gentle until the new portion anchors.

Propagate only healthy growth. Allow recently imported, melting, or algae-covered plants to recover first.

Normal adjustment

Transport, planting, and conversion from nursery growth can cause temporary melting, pale leaves, or slow spreading.

  • Normal signs include firm crowns, fresh white roots, new runners, creeping tips, or newly formed submerged leaves.
  • Emersed-grown leaves may melt while new submerged growth develops.
  • Colour and height may change over several weeks.

Signs needing attention

  • Soft crowns, transparent new growth, repeated loss of every new runner, or spreading decay.
  • A carpet lifting from the substrate because the lower layer has died.
  • Heavy algae or debris covering new growth.
  • Repeated uprooting by fish, shrimp maintenance, or excessive direct flow.

Japan is an aquarium trade form. It can grow upward or climb over neighbouring plants when light is low or trimming is delayed.

Suitability and Problems

Shrimp suitability
Excellent
Goldfish resistance
Low
Fish damage risk
Moderate high
Melt risk
Moderate
Algae susceptibility
Moderate

Common problems

  • Freshly planted portions float or pull out: The plugs may be too large, planted too shallowly, exposed to strong direct flow, or disturbed by fish.
  • Carpet grows upward instead of spreading: Insufficient light at substrate level, crowding, shading, or unstable CO₂ may contribute.
  • Lower carpet turns brown and lifts: The mat may be too thick, with poor light and circulation reaching the lower layer.
  • Leaves melt after planting: Transport stress, emersed-to-submersed conversion, damaged roots, or unstable conditions may be involved.
  • Algae or debris covers the foreground: Slow establishment, excessive light, unstable CO₂, weak circulation, or overfeeding may contribute.

Do not diagnose from appearance alone

Yellowing, transparent leaves, holes, twisted runners, pale tips, or slow spreading do not prove one nutrient deficiency. Similar signs can result from unstable CO₂, unsuitable light, damaged roots, adaptation, temperature stress, algae, poor circulation, or repeated uprooting.

Safe checking order

  • Review recent water, temperature, lighting, and equipment changes.
  • Check whether CO₂, if used, starts consistently and remains stable during the light period.
  • Compare symptoms on new growth with symptoms on older leaves.
  • Inspect roots, crowns, runners, and the underside of the carpet for decay.
  • Review fertiliser dosing and root nutrition where applicable.
  • Check light intensity and duration rather than assuming more light will solve slow growth.
  • Change one variable at a time and judge improvement from new growth.

Old damaged leaves will not repair themselves. Assess the next runners or leaves after making a change.

Who this plant suits

  • Beginner tanks: Generally suitable for beginners when planted correctly and given room to spread.
  • Shrimp tanks: generally suitable after rinsing and quarantine, with carpets offering grazing and shelter.
  • Low-tech tanks: easiest with runner plants such as Sagittaria, Helanthium, and Marsilea when slower or taller growth is acceptable.
  • High-tech tanks: useful for dense carpets, compact form, and faster recovery when CO₂ and fertilising remain stable.
  • Nano aquariums: suitable for low carpet plants, but tall forms need more height and regular control.
  • Community aquariums: suitable with fish that do not dig, uproot, or constantly graze the foreground.

Important limitations

  • Goldfish, digging cichlids, large plecos, and active bottom fish can uproot carpets and runners.
  • Dense carpets can trap waste and may lift when lower growth dies.
  • Fast runner plants may enter neighbouring planting areas.
  • Japan is an aquarium trade form. It can grow upward or climb over neighbouring plants when light is low or trimming is delayed.

Plant Decision Guide

  • Choose it for fast green carpets, low bushes, and growth draped over hardscape.
  • Choose a runner plant when you want gradual natural spreading and can remove unwanted daughter plants.
  • Choose a creeping stem carpet when you can trim it regularly and keep CO₂ and fertilising consistent.
  • Think carefully if the aquarium is new, algae-prone, or contains digging fish.
  • Think carefully if fine planting and repeated replanting are not practical.
  • Inspect the actual specimen because aquarium cultivar names and final heights are not always consistent.

Identification and Origin

Accepted name
Hydrocotyle tripartita
Genus
Hydrocotyle
Species epithet
tripartita
Family
Araliaceae
Cultivar
Japan
Origin
Australia, Cultivar, New Zealand

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