If your Anubias leaves are turning yellow, don’t panic. It’s one of the most common issues Anubias owners run into, and it’s almost always fixable once you know the cause. In most cases, yellowing comes down to too much light, a nutrient imbalance, or simply old leaves reaching the end of their natural lifespan. Below, we’ll walk through how to tell these apart and exactly what to do about each one.
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Note: Anubias is popular in both terrariums (grown emersed, out of water) and aquariums (grown submersed, underwater). The causes below apply to both, but we’ll flag where the fix differs.
Quick Answer
The most common cause of yellowing Anubias leaves is too much direct light. Anubias is a low-light, shade-tolerant plant, and bright light stresses it before it stresses faster-growing species. The second most common cause is a nutrient deficiency, particularly iron or nitrogen.
If only the oldest, bottom leaves are yellowing while new growth stays healthy, that’s normal aging and nothing to worry about.
For general species care basics, see our Anubias Nana Petite care guide.
Common Causes of Yellow Anubias Leaves
Too Much Light
Anubias evolved growing in the shaded understory of slow-moving streams and rainforest floors. That’s why it tolerates low light better than almost any other terrarium or aquarium plant, but it also means too much light does real damage. Excess light, especially direct sun or a high-intensity grow light placed too close, causes the leaves to bleach and yellow, sometimes with visible algae growth on the leaf surface as a secondary symptom.
If you’re deciding on a light source for a new setup, our best terrarium lighting guide covers intensity levels that work for shade-tolerant plants like Anubias.
Nutrient Deficiency
In low-tech aquarium setups especially, Anubias can develop yellowing from a lack of iron or nitrogen.
This typically shows up as yellowing between the leaf veins while the veins themselves stay green (a pattern called interveinal chlorosis), a classic sign of iron deficiency.
According to the University of Florida IFAS Extension, interveinal chlorosis in aquatic and tropical plants is most often linked to iron or magnesium deficiency rather than nitrogen alone, so it’s worth ruling out both. In terrarium setups, this is less common but can happen if the plant has been in the same substrate for a long time without any fertilization.
Natural Old-Leaf Shedding
Anubias leaves are tough and long-lived, but they don’t last forever. If you notice only the oldest leaves near the base of the rhizome turning yellow and eventually dying back, while new leaves continue to emerge green and healthy, this is completely normal. Plants routinely shed older leaves to redirect energy to new growth.
CO2 or Fertilizer Imbalance (Aquarium Setups)
In planted aquariums running CO2 injection or a heavier fertilizing schedule, an imbalance (too much of one nutrient relative to another) can trigger yellowing as the plant struggles to process what it’s being given. This is more common in higher-tech tanks than in simple low-tech setups.
Poor Water Flow or Algae Smothering (Aquarium Setups)
Anubias leaves are broad and slow-growing, which makes them a magnet for algae if water flow is poor or nutrients are out of balance elsewhere in the tank. A layer of algae on the leaf surface blocks light the plant does need, which can cause yellowing underneath.
How to Fix Yellowing Anubias
- Move it out of direct or intense light. If your Anubias is in a spot with direct sun or sitting close to a strong grow light, relocate it to a shadier spot or increase the distance from the light source. Improvement usually shows within 1 to 2 weeks on new growth (yellowed leaves typically won’t turn green again, see below).
- Add a root tab or liquid fertilizer with iron. For aquarium Anubias, tuck a root tab near the rhizome (without burying the rhizome itself) or dose a liquid fertilizer containing chelated iron. For terrarium Anubias, a diluted liquid fertilizer applied sparingly every few weeks is usually enough. See our terrarium soil and substrate guide if you suspect the substrate itself is nutrient-depleted.
- Trim off old yellow leaves. Once a leaf has fully yellowed, it won’t recover. Trimming it frees up the plant’s energy for new growth and improves airflow and light to the rest of the plant. Cut close to the rhizome with a clean, sharp terrarium plant trimmer.
- Check and stabilize your fertilizing and CO2 routine. If you’re running CO2 or a fertilizing schedule, keep it consistent rather than sporadic. Inconsistency is often more damaging than a slightly lower overall dose.
- Improve water flow and manually remove algae. Gently wipe algae off leaves with your fingers or a soft terrarium glass cleaning tool, and check that your filter is providing adequate circulation across the whole tank, not just near the outlet.
How to Tell the Difference Between Normal Aging and a Problem
- Only old, bottom leaves affected, new growth is green: normal aging, no action needed beyond trimming
- New leaves emerging yellow or pale: lighting or nutrient issue, needs a fix
- Yellowing between veins, veins stay green: likely iron deficiency
- Whole leaf yellowing uniformly, plant near a bright light source: likely too much light
- Yellowing plus algae on the leaf surface: light and/or flow issue in an aquarium setting
How to Prevent It Going Forward
- Keep Anubias in low to moderate light. If you can comfortably read in the spot without extra lighting, it’s usually about right.
- Fertilize lightly but consistently rather than heavily and sporadically.
- Trim old leaves proactively every few months rather than waiting for them to fully yellow.
- If in an aquarium, keep an eye on flow near the Anubias to prevent algae buildup.
- If you’re setting up a new low-tech planted tank, our guide to Anubias vs Bucephalandra can help you pick species suited to your light setup from the start.
FAQ
Should I cut off yellow Anubias leaves?
Yes. Once a leaf turns yellow, it won’t turn green again, and removing it lets the plant redirect energy toward healthy growth.
Can yellow Anubias leaves turn green again?
No. A fully yellowed leaf is done. The goal is to fix the underlying cause so new leaves grow in healthy, not to try to revive old ones.
Is yellow Anubias contagious to other plants?
No, yellowing itself isn’t contagious. It’s an environmental response, not a disease. But if the cause is an algae or light issue affecting one plant, it’s worth checking whether other plants nearby are showing early signs too.
According to the Royal Horticultural Society, most leaf yellowing in houseplants and aquatic plants traces back to light, water, or nutrient stress rather than pathogens, so treat it as an environmental fix first.