Pearl Weed
Hemianthus micranthemoides
A versatile bright-green stem plant that can be grown tall or trimmed low into a carpet.
| Care Difficulty | Beginner |
| Lighting | Medium to High |
| CO2 Requirement | Optional |
| Growth Rate | Fast |
| Placement | Foreground/Midground |
Overview
Pearl Weed (Hemianthus micranthemoides) is a versatile bright-green stem plant that can be grown tall or trimmed low into a carpet. It is a beginner-level aquarium plant, making it a great choice for beginners and low-tech tanks.
This guide covers how to grow Pearl Weed successfully - its appearance and growth habit, lighting needs, whether it needs CO2, fertilising, planting and placement, propagation, and the common problems to avoid.
Appearance & Growth Habit
A versatile bright-green stem plant that can be grown tall or trimmed low into a carpet.
It is a fast grower used in the foreground/midground of the aquascape. Fast growth means regular trimming, but it also makes the plant a powerful nutrient sponge that helps starve out algae.
Lighting Requirements
Pearl Weed grows best under medium to high lighting. It needs strong, even light reaching its leaves, so use a good planted-tank LED.
Run lights on a timer for about 6-8 hours a day. Longer photoperiods usually feed algae rather than plants, so increase duration cautiously and watch for any green film.
CO2 & Fertilisation
CO2: Optional. CO2 is optional - it speeds and improves growth but is not essential.
Dose a balanced liquid fertiliser (such as API Leaf Zone) for water-column nutrients, and add root tabs beneath heavy root-feeders. Yellowing, holes or stunted leaves usually signal a nutrient deficiency, not disease.
Planting & Placement
Plant or attach Pearl Weed in the foreground/midground. Plant small portions into the substrate, spacing them so they grow together over time.
Propagation
Trim and replant the cuttings; frequent trimming encourages dense, low growth.
Sharing trimmings is part of the fun of the hobby - one healthy plant can fill a tank and stock several more over time.
Common Problems
The most common issue is algae on the leaves, which points to too much light, too few nutrients or weak flow rather than a fault with the plant. Melting (leaves dissolving) after planting is normal as it converts to underwater growth - keep conditions stable and new growth follows.
Keep light, CO2 and fertilisation consistent, remove dying leaves promptly, and avoid burying the crown or rhizome of plants that grow from one.
Is Pearl Weed Right for Your Tank?
Pearl Weed is an easy, rewarding plant that suits almost any freshwater tank, including beginner and low-tech setups. Combine it with our other plant and aquascaping guides to build a lush, balanced planted aquarium.