A Pearl weed either thrives or melts within the first month, and the difference is almost always down to three things you can control. The Hemianthus micranthemoides Pearl weed is a workhorse plant for a reason: it tolerates a wide range of conditions and still looks good doing it.
At a glance
| Light | high |
|---|---|
| Temperature | 22 to 28 °C |
| pH | 6.0 to 7.5 |
| Height | 10 to 30 cm |
| CO₂ | beneficial |
| Growth | fast |
Planting
Plant Pearl weed with the crown or rhizome clear of the substrate — burying it rots the base. In a 26-gallon tank, position it mid-ground or background depending on its height. Weaker setups do fine; pair it with the pygmy chain sword guide for a layered look.
Light and CO₂
Run 8 hours of light a day on a timer to avoid algae swings. Pearl weed grows under high light and beneficial, though a small, steady dose of liquid fertiliser every 3 weeks pushes denser growth.
Propagation
Trim and replant tops; it bushes out under strong light.
Common issues
Yellowing lower leaves usually mean a nutrient gap, not too little light. Trim dying leaves at the base, keep nitrates around 10 to 20 ppm, and avoid moving the plant every week — a solid lymphocystis: the 'cauliflower' wart virus in fish explains why stability beats tinkering.
Low-light reality
Under low light the Pearl weed grows slower and stays compact, which is ideal for a low-tech tank. Run 8 hours of light on a timer and skip CO₂; a light liquid fertiliser every few weeks is enough.
