*Pearlweed*, scientifically known as *Hemianthus micranthemoides*, is a versatile and popular aquatic plant in the aquarium hobby. It's appreciated for its small, round leaves and its ability to create dense, carpet-like mats or bushy clusters in planted tanks. Here are some key points about pearlweed:

1. **Appearance**: Pearlweed has small, bright green leaves that grow closely together along creeping stems. In low light conditions, the leaves may elongate slightly, but under higher light, they remain compact and dense.

2. **Lighting**: Pearlweed does well in moderate to high lighting conditions. Higher light levels promote compact growth and more vibrant green coloration. However, it can adapt to lower light conditions as well.

3. **Water Conditions**: It thrives in slightly acidic to neutral pH levels (around 6.0-7.5) and temperatures between 68-82°F (20-28°C). Regular water changes help maintain its health and appearance.

4. **Substrate**: Pearlweed can be planted in nutrient-rich substrates, but it can also grow well in plain gravel or sand. Adding root tabs or liquid fertilizers enhances its growth rate and vibrancy.

5. **CO₂ and Nutrients**: Providing CO₂ supplementation can significantly boost growth and help maintain dense mats of pearlweed. Regular fertilization with a balanced liquid fertilizer ensures it receives essential nutrients.

6. **Propagation**: Propagation is straightforward through stem cuttings. Simply cut a healthy stem and replant it into the substrate. It quickly develops roots and continues to spread horizontally.

7. **Placement**: Pearlweed is versatile and can be used in various parts of the aquarium. It can be used as a foreground carpeting plant, midground filler, or even as a background bushy cluster depending on trimming and maintenance.

8. **Compatibility**: It is compatible with most freshwater fish and invertebrates. Its dense growth provides cover and shelter, making it beneficial for aquarium inhabitants.

9. **Maintenance**: Regular trimming is necessary to control its growth and maintain its desired shape. Trimming encourages lateral growth and prevents the plant from becoming too dense or shading other plants.

Pearlweed is favored by aquascapers for its ease of care and ability to create lush, green carpets or clusters in planted aquariums. If you have more specific questions or need further information about pearlweed or any other aquatic plants, feel free to ask!