Species guide
Pearl Weed Care Guide (Hemianthus micranthemoides)
Aquatic plant
Pearl weed (Hemianthus micranthemoides) makes a bright green bush or loose carpet with round leaves on a stem — not the pin-leaf mat of HC Cuba and not the low runner of Monte Carlo. Medium light and optional CO₂; trim often or it goes leggy.
- Stem / bush
- Round leaves
- Medium light
- Not HC / MC
Quick facts
| Light | Medium–high for tight bush; low = leggy |
|---|---|
| CO₂ | Optional; helps density |
| Temp | 20–26 °C |
| Planting | Stems in soil 2–3 cm apart or float to root |
| Trim | Pinch tops weekly to branch |
| vs HC Cuba | HC = tiny carpet, high-tech. Pearl = bigger leaf, easier |
| vs Monte Carlo | MC = Micranthemum tweediei carpet. Different genus |
| vs Glosso | Glosso = runners on soil. Pearl = stem bush |
Overview
Same shop shelf, three different jobs. HC Cuba is pin-leaf high-tech carpet. Monte Carlo is the forgiving Micranthemum lawn. Glosso is runner Iwagumi. Pearl weed is Hemianthus micranthemoides — a bushy midground or loose foreground you trim like a stem.
Stem issues: lower leaves melting. Triangle: light/CO₂/fert. Easy neighbors: Hygrophila polysperma · water wisteria.
Bush it or carpet it loose
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Step 1
Plant stems shallow in groups
2–3 cm apart in aquasoil. One thick wad rots at the base.
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Step 2
Medium–high light for a tight pearl look
Low light stretches between nodes — still alive, just ugly.
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Step 3
Pinch tops to force side shoots
Weekly once it grows. Sell or discard trimmings — they replant.
-
Step 4
CO₂ if you want a dense mat
Survival without gas is fine. Carpet density usually wants CO₂ + soil.
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Step 5
Don't confuse with HC at the shop
Pearl leaves are visibly rounder and larger than Cuba.
Common problems
Leggy stems, bare lower section
Why: Low light or never trimmed.
Fix: Raise PAR; replant tops; see <a href="{EN['stem']}">stem lower leaves</a>.
Melts after planting
Why: Emersed tissue + shock.
Fix: Leave roots; stable CO₂ if used; don't uproot daily.
Algae on tips
Why: Excess light hours or dirty water.
Fix: Shorten day; more flow; shrimp on tips.
Never carpets, only floats up
Why: Not enough light at substrate or wrong species sold.
Fix: More PAR or accept midground bush role.
Tank mates
Gear for this species
Landen Aqua Soil Substrate for Natural Planted Aquarium, Plant or Shrimp Stratum, Clay Gravel and Stable Porous Substrate for Freshwater Aquarium, Black Color 40lbs
Substrate vàng chuẩn Iwagumi / Nature Aquarium.
Budget low-tech under $150 — Pearl weed is bushy Hemianthus — easier than HC, not a Monte Carlo clone
FAQ
Pearl weed vs HC Cuba?
Different species. HC has tiny leaves and wants high-tech carpet care. Pearl weed is bushier and easier.
Pearl weed vs Monte Carlo?
Monte Carlo is Micranthemum tweediei — true carpet runner. Pearl weed is Hemianthus micranthemoides — stem bush.
Can it replace glosso?
No. Glosso spreads runners flat. Pearl grows upward unless heavily trimmed.
Need CO₂?
Optional. Bush yes; tight carpet usually needs gas.
Will it pearl (O₂ bubbles)?
Sometimes under high light + CO₂. Not like Riccia — see Riccia for that stunt.
Good beginner stem?
Yes — easier than HC, similar trim habit to Hygro.
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