Easy plants with no CO2 for beginners
People often assume a beautiful planted tank demands a CO2 cylinder and complicated kit. It doesn’t: many gorgeous plants grow with no injected CO2 at all. For a first planted tank, it’s actually the way to go. Here are the safe bets.
The bottom line. A no-CO2 planted tank works brilliantly with the right species: Anubias, Java fern, Cryptocoryne, Vallisneria, Hygrophila, Elodea and mosses. Give them moderate lighting (6–8 h/day), a little fertilising and some patience: growth is slower without CO2, but these plants are almost impossible to kill.
Why these plants work without CO2
Plants use carbon to grow. With injected CO2 they have it in abundance and grow fast. Without CO2, the available carbon is limited: only plants that can make do with little will thrive. These are tough species with slow or moderate growth that also tolerate a wide range of conditions, perfect for getting started.
The secret to an easy no-CO2 planted tank is to plant densely from day one with easy species. Lots of plants fill the space, use up the spare nutrients and leave less room for algae. A half-empty tank is an algae tank.
7 easy plants with no CO2
| Plant | Position | Quirk |
|---|---|---|
| Anubias (barteri, nana) | Attached to rock/wood | Rhizome NEVER buried · bulletproof |
| Java fern (Microsorum) | Attached to rock/wood | Very tolerant · rhizome above the substrate |
| Cryptocoryne | Foreground/midground, in the substrate | ”Melts” on setup, then bounces back |
| Vallisneria | Background | Long leaves · grows fast |
| Hygrophila | Background | Sturdy stem · trim regularly |
| Elodea / Egeria | Floating or planted | Fast growing · soaks up nutrients |
| Java moss | On any surface | Great for shrimp · no fuss at all |
Two golden rules:
- Anubias and Java fern attach to a rock or piece of wood — their rhizome must never be buried (it rots if it is).
- Cryptocoryne often “melt” after you buy them (the leaves wither away), then come back stronger. Don’t pull them out: it’s normal.
The conditions for success
- I've chosen easy species (Anubias, Java fern, Crypts, mosses…)
- Moderate lighting, 6 to 8 h/day (ideally on a timer)
- A little fertilising (nutrient substrate or light liquid fertiliser)
- Anubias and Java fern rhizomes NOT buried
- I've planted densely from the start
- I'm patient: growth is slower without CO2
If I could only recommend one plant for a first tank, it would be Anubias: tie it to a piece of wood, forget about it, and it survives almost anything. Ideal for building confidence before you move on to more demanding species.
Conclusion
You don’t need CO2 for a beautiful planted tank: with Anubias, Java fern, Cryptocoryne, Vallisneria, Hygrophila, Elodea and mosses, you’ve got everything you need to succeed. Moderate lighting, a bit of fertilising, dense planting and patience — your plants will do the rest, and keep algae at bay.
For the substrate to go with them, read Best substrate for a no-CO2 nano tank. And if algae show up despite everything, see How to get rid of green hair algae.
Frequently asked questions
Can you have a planted aquarium without CO2?
Yes, absolutely. Plenty of tough plants grow very well without injected CO2, as long as you choose the right species, moderate lighting and a bit of fertilising. It's the simplest way to start a planted tank.
What are the easiest plants without CO2?
The safe bets are Anubias, Microsorum (Java fern), Cryptocoryne, Vallisneria, Hygrophila, Elodea and mosses (Java moss). They tolerate a wide range of conditions and forgive a shaky start.
Do easy no-CO2 plants need fertilising?
A little, yes. Even tough plants use up nutrients. A nutrient substrate or a light liquid fertiliser is enough. With no fertilising at all and an inert substrate, even easy plants eventually stall.
Why do my easy plants melt anyway?
Usually because of adaptation (Cryptocoryne 'melt' then bounce back), a lack of light or nutrients, or a plant buried too deep (the rhizome of Anubias and ferns must never be buried).
