Guppy Grass
Najas guadalupensis
Synonyms Najas grass · Southern waternymph
Guppy Grass (Najas guadalupensis) is a stem plant for the background, growing to about 60 cm (23.6 in) at a fast pace. It wants 59–86°F (15–30°C), low light and no CO₂, and counts as an easy plant to keep alive.
At a glance
| Type | Stem plant |
|---|---|
| Light | LowThe least light it survives in, not the light it looks best in. |
| CO₂ | Not neededWhether it survives without added CO₂ — not whether CO₂ would help it grow faster. |
| Difficulty | Easy |
| Temperature | 59–86°F (15–30°C) |
| Max height | 60 cm (23.6 in)Grown submersed, left to mature, never trimmed. |
| Growth rate | Fast |
| Placement | planted in the background |
| pH | 6–8 |
Before it goes in
- Guppy Grass lives under a plain low-light LED — it does not need a planted-tank lamp to survive.
- It grows without CO₂.
- At about 60 cm (23.6 in) it belongs behind everything shorter — planted at the front it hides the rest of the scape and shades it.
- Its leaves are medium: Goldfish, Electric Yellow Lab and Colombian Ramshorn Snail will eat it.
Can it grow without CO₂?
Yes. Guppy Grass does not need CO₂ at all.
How much light does it need?
Low light is enough — and that is the survival line, not the “it looks better” line.
How big does it get?
About 60 cm (23.6 in) tall when it is mature and untrimmed, growing fast, and it does not root at all.
Will my fish eat it?
Its leaves are medium, so some will: Goldfish, Electric Yellow Lab and Colombian Ramshorn Snail.
What it goes with
- Plants that run on the same light and CO₂, so they can share a tank without one of them being the odd one out: Water Sprite, Anubias nana 'Petite', Cryptocoryne wendtii and Frogbit.
- Animals that share its temperature range and will not eat or uproot it: Betta, Cherry Shrimp, Angelfish and Bristlenose Pleco.
Often compared with
| Guppy Grass | Brazilian Pennywort | Cabomba | |
|---|---|---|---|
| Light | Low | Low | Medium |
| CO₂ | Not needed | Not needed | Recommended |
| Max height | 60 cm | 60 cm | 60 cm |
| Difficulty | Easy | Easy | Medium |
More plants
Sources (1)
- tropica.comSep 2026