Knowledge Centre · Planted aquariums
Best beginner aquarium plants: Java fern, Anubias and more compared
Six plants come up repeatedly as genuinely easy, not just marketed as easy: Java fern, Anubias, Cryptocoryne, Vallisneria, Java moss and Amazon sword. All six grow well without CO2 injection and tolerate a wide range of lighting and water conditions — but they're not interchangeable, and the single most common way beginners kill two of them (Java fern and Anubias) is entirely avoidable once you know what to check. This guide compares all six on light, CO2, substrate and the specific things worth getting right with each.
Before you buy
This guide helps if…
You want plants that will genuinely survive and grow in a low-tech, no-CO2 tank, and you want to know which specific care point matters for each species before you plant it.
Worth knowing: "easy" doesn't mean "no care points." Java fern and Anubias in particular are frequently killed by one specific, avoidable planting mistake — covered in detail below, since it's common enough to be worth understanding before you buy either.
Java fern
An epiphyte native to Southeast Asia, grown attached to wood or rock rather than planted in substrate. Tolerates low to moderate light and doesn't need CO2 injection[1], making it one of the most forgiving plants available for a low-tech tank. Slow-growing, which cuts both ways: low maintenance, but not a quick fix if you're hoping to establish cover fast. See rhizome rot below before planting — this is the single most common way this species is killed.
Anubias
Another epiphyte, tolerant of low to moderate light and not requiring CO2 supplementation[1]. Broader, thicker leaves than Java fern, and even more forgiving of low light — a genuinely good choice for a dim corner of a tank other plants would struggle in. Slow-growing like Java fern, and subject to the same rhizome-burial risk covered next. See our dedicated Anubias care guide for the varieties, propagation and why algae seems to target its leaves especially.
Why Java fern and Anubias die: rhizome rot
Cryptocoryne
A substrate-rooted genus available in a wide range of leaf shapes, sizes and colours, adapting well to low-tech setups and a range of water conditions[1]. Unlike Java fern and Anubias, Cryptocoryne benefits from root feeding, so a nutrient-rich substrate or root tabs matter more here. Worth knowing: Cryptocoryne is reported to sometimes shed most of its leaves ("crypt melt") after being moved or when water parameters change significantly — this is usually a stress response the plant recovers from via new growth from its root system, not necessarily plant death, so it's worth being patient rather than immediately discarding a melted crypt.
Vallisneria
A fast-growing, grass-like substrate-rooted plant that tolerates a wide range of lighting and water conditions and doesn't need CO2 injection[1]. Its long, ribbon-like leaves make it a good background or mid-ground choice, and it spreads via runners over time. One specific caution: Vallisneria is documented as sensitive to glutaraldehyde-based liquid carbon supplements, which can damage or kill it even at label doses[1] — avoid liquid carbon products entirely if Vallisneria is part of your planting.
Java moss
Grows attached to wood, rock or mesh rather than planted in substrate, tolerates low light and no CO2, and is commonly used to create texture on hardscape or as fry/shrimp cover[1]. Fast-growing relative to Java fern and Anubias, needing more regular trimming to keep it from becoming a dense, debris-trapping mat if left unchecked. Doesn't have a rhizome, so it isn't subject to the rhizome-rot risk covered above — it can be tied or glued to hardscape directly.
Amazon sword
A substrate-rooted plant tolerant of low-to-medium light and not requiring CO2, commonly used as a background centrepiece plant given its eventual size[1]. Of the six plants here, Amazon sword benefits most clearly from root feeding — a nutrient-rich substrate or root tabs specifically, since it's a heavier root feeder than Cryptocoryne. Grows considerably larger than the other five over time, so it's worth planning space for its mature size rather than the smaller size it's typically sold at.
Comparison at a glance
| Plant | Attachment | Light tier | Key care point |
|---|---|---|---|
| Java fern | Epiphyte (wood/rock) | Low | Never bury the rhizome |
| Anubias | Epiphyte (wood/rock) | Low | Never bury the rhizome |
| Cryptocoryne | Substrate-rooted | Low | May melt after moving or a parameter change; usually recovers |
| Vallisneria | Substrate-rooted | Low–medium | Avoid glutaraldehyde-based liquid carbon |
| Java moss | Epiphyte (no rhizome) | Low | Trim regularly to prevent a dense debris-trapping mat |
| Amazon sword | Substrate-rooted | Low–medium | Heaviest root feeder of the six; plan for its large mature size |
Mixing tiers in one tank
All six plants sit at the low or low-medium end of the light-tier scale, so they combine well in the same low-tech tank without one outcompeting another for light. The main planning consideration is attachment method rather than light: epiphytes (Java fern, Anubias, Java moss) need hardscape to attach to and shouldn't be planted in substrate, while the substrate-rooted three (Cryptocoryne, Vallisneria, Amazon sword) need enough open substrate and, for Amazon sword especially, enough eventual space for a much larger mature plant. See our lighting guide for the PAR tiers behind these light recommendations in more depth.
Common mistakes
- Burying the rhizome of Java fern or Anubias, the single most common way both are killed.
- Discarding a Cryptocoryne after "crypt melt" rather than waiting to see if it recovers from the root system.
- Dosing glutaraldehyde-based liquid carbon in a tank with Vallisneria.
- Letting Java moss grow into a dense, undivided mat without regular trimming, trapping debris underneath.
- Planting Amazon sword without accounting for its eventual size, crowding out neighbouring plants as it matures.
Frequently asked questions
Why do Java fern and Anubias die after planting?
Almost always the same mistake: burying the rhizome (the thick horizontal stem the leaves and roots grow from) in the substrate. Both are epiphytes, meaning they naturally grow attached to hard surfaces like wood or rock rather than rooted in substrate, and a buried rhizome is cut off from light and water flow, causing it to rot. The fix is to attach the rhizome to décor with thread or aquarium-safe glue, or simply rest it on the substrate surface, with only the roots (not the rhizome itself) allowed into the substrate.
Which beginner aquarium plants don't need CO2?
All six plants compared on this page — Java fern, Anubias, Cryptocoryne, Vallisneria, Java moss and Amazon sword — grow successfully on ambient CO2 alone, without injection. CO2 can speed up growth and improve colouration in some of them, but none require it to survive and grow in a typical low-tech setup.
Can I use liquid carbon fertiliser with Vallisneria?
Avoid it. Vallisneria is documented as sensitive to glutaraldehyde-based liquid carbon products, which can damage or kill it even at label doses. If Vallisneria is part of your planting, either skip liquid carbon supplements entirely or choose an alternative species for the rest of your tank if you specifically want to dose liquid carbon.
Do any of these beginner plants need root tabs or a nutrient-rich substrate?
Amazon sword and, to a lesser extent, Cryptocoryne benefit from root feeding — a nutrient-rich substrate or root tabs pushed near their root system. Java fern, Anubias, Java moss and Vallisneria draw most of their nutrients from the water column instead, so root feeding matters far less for them specifically.
How AquaPulse can help
These six plants are genuinely tolerant of a range of conditions, which makes them forgiving but also easy to stop actively monitoring — a slow decline can go unnoticed for longer with hardy plants than with something visibly demanding. That's more relevant to the fish and shrimp sharing the tank than the plants themselves: a planted tank's water quality still matters for its livestock even when the plants look fine.
AquaPulse works from the readings and context you enter — it doesn't measure your water automatically. Logging your regular test results in AquaPulse keeps that comparison available, so a genuine drift is something you can check rather than assume the plants would have shown you first. Get AquaPulse on the App Store or Google Play to try it, or see the Water Check feature page for more detail.
Sources and editorial information
- Published
- 8 August 2026
- Last reviewed
- 8 August 2026
- Written and maintained by
- AquaPulse (Valeon Labs Ltd)
This guide draws on specialist aquatic-plant retail and hobbyist sources for species-level light, CO2 and substrate detail, cross-checked across independent sources for the rhizome-rot mechanism specifically given how consequential that single mistake is. Where a care detail (such as "crypt melt" recovery) reflects widely reported hobby experience rather than a controlled study, we've presented it as such. We'll update this page if we find something we've got wrong.
Good to know: This guide provides general informational guidance only. It does not recommend a specific supplier or product, and individual plant health varies with water conditions, lighting and care beyond what any general guide can guarantee.
- [1] Aqua Essentials — "Aquarium Plants That Don't Need CO2 (Easy Beginner Plants)" Specialist aquatic-plant retailer source. Used for the light-tier, CO2-independence and Vallisneria/liquid-carbon sensitivity detail for all six species. Not a scientific authority; presented as widely reported hobby consensus.
- [2] Aquarium Co-op — "How do I plant my Anubias, Java fern, or other rhizome plant?" Specialist aquarium-retail hobbyist source, already used elsewhere on this site. Used directly for the rhizome-rot mechanism and correct planting method. Not a scientific authority; presented as widely reported, consistently corroborated hobby knowledge.
What we deliberately left out: a numeric water-parameter range (pH, hardness, temperature) for each species, since all six are widely reported to tolerate a broad range and a precise figure would overstate how narrow their actual requirements are; and any variety- or cultivar-specific detail (dwarf vs standard Anubias, Cryptocoryne species-level differences), since this guide is scoped to genus/species-general beginner guidance rather than a full varietal breakdown.