A Pygmy chain sword either thrives or melts within the first month, and the difference is almost always down to three things you can control. The Helanthium tenellum Pygmy chain sword is a workhorse plant for a reason: it tolerates a wide range of conditions and still looks good doing it.
At a glance
| Light | medium |
|---|---|
| Temperature | 22 to 28 °C |
| pH | 6.0 to 7.5 |
| Height | 5 to 12 cm |
| CO₂ | optional |
| Growth | moderate |
Planting
Plant Pygmy chain sword with the crown or rhizome clear of the substrate — burying it rots the base. In a 35-gallon tank, position it mid-ground or background depending on its height. Weaker setups do fine; pair it with our otocinclus breeding guide for a layered look.
Light and CO₂
Run 8 hours of light a day on a timer to avoid algae swings. Pygmy chain sword grows under medium light and optional, though a small, steady dose of liquid fertiliser every 2 weeks pushes denser growth.
Propagation
Runners form a low carpet over weeks.
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 — our marimo moss ball care: the round, slow green pet guide explains why stability beats tinkering.
Low-light reality
Under low light the Pygmy chain sword grows slower and stays compact, which is ideal for a low-tech tank. Run 9 hours of light on a timer and skip CO₂; a light liquid fertiliser every few weeks is enough.
