Plant comparison
Glossostigma vs Pogostemon Helferi (Downoi)
How the Glossostigma and Pogostemon Helferi (Downoi) compare on care, size, water and temperament, and which plant suits your tank.
By Mike ElmiraUpdated
TL;DR, Glossostigma vs Pogostemon Helferi (Downoi)
The Glossostigma and the Pogostemon Helferi (Downoi) come up together a lot when people are choosing a plant, and they are close enough to weigh side by side. Both are happy somewhere around 22 to 26 °C and pH 6 to 7, so a single tank can suit either one. The Pogostemon Helferi (Downoi) is the more forgiving of the two, which matters if this is an early tank, while the Glossostigma rewards a bit more attention. Read the full care notes on each below and pick the one whose look and pace fit the tank you're building.
Group compatibility overview
Excellent fit
Every key parameter overlaps and no major conflicts surfaced.
1 note
Temperature
- Glossostigma20–26 °C
- Pogostemon Helferi (Downoi)22–28 °C
pH
- Glossostigma5.5–7
- Pogostemon Helferi (Downoi)6–7.5
Hardness
- Glossostigma1–10 dGH
- Pogostemon Helferi (Downoi)2–15 dGH
What to plan for
- Demanding species presentGlossostigma are difficulty 4+. Stable parameters and weekly maintenance are non-negotiable.
Full attributes
Every parameter, side by side| Parameter |  PlantGlossostigmaGlossostigma elatinoides |  PlantPogostemon Helferi (Downoi)Pogostemon helferi |
|---|---|---|
| Category | Plant | Plant |
| Origin | New Zealand, southeastern Australia | Thailand, Myanmar |
| Family | Phrymaceae | Lamiaceae |
| Temperature | 20–26 °C | 22–28 °C |
| pH | 5.5–7.0 | 6.0–7.5 |
| Hardness (dGH) | 1–10 | 2–15 |
| Flow rate | Low to Medium | Medium |
| Max height | 1–3 cm | 5–12 cm |
| Difficulty | 4 / 5 | 3 / 5 |
| Light | High | Medium to High |
| CO₂ | Required | Recommended |
| Growth rate | Fast | Medium |
Frequently asked questions
Direct answers to the questions search engines and AI assistants surface most often about this species.
Can you keep Glossostigma and Pogostemon Helferi (Downoi) together?
Yes. Their temperature and pH ranges overlap around 22 to 26 °C and pH 6 to 7, so one set of water conditions keeps both comfortable. Match group sizes and cover the usual planted-tank basics and they share a tank fine.
Which is easier to keep, the Glossostigma or the Pogostemon Helferi (Downoi)?
The Pogostemon Helferi (Downoi) is the easier of the two, closer to middle-of-the-road, while the Glossostigma leans demanding.
Do Glossostigma and Pogostemon Helferi (Downoi) need the same water?
Close to it. Aim for 22 to 26 °C and pH 6 to 7 and you're in the shared sweet spot for both. Full ranges are in the table above.
What's the main difference between the Glossostigma and the Pogostemon Helferi (Downoi)?
Placement and light. The Glossostigma works as foreground, the Pogostemon Helferi (Downoi) as foreground or midground, and their light needs differ, which is covered in the table.