Anubias Nana Turning Brown – Your Complete Diagnostic & Revival Guide

Written ByHoward Parker

There’s nothing quite like the sinking feeling you get when you spot it. That beautiful, hardy, deep-green Anubias Nana—the plant everyone told you was “impossible to kill”—is starting to look sad. Its leaves, once a vibrant centerpiece, are now showing unwelcome shades of brown. I’ve been there, and I know how frustrating it can be.

You’re probably wondering what you did wrong. Is your water bad? Is the light wrong? Did you just get a bad plant? Don’t worry. Seeing your anubias nana turning brown is one of the most common problems aquarists face, but the good news is that it’s almost always fixable.

I promise that by the time you finish this guide, you’ll not only understand exactly why your Anubias is struggling, but you’ll also have a clear, step-by-step action plan to nurse it back to health. Imagine your plant looking lush and green again, contributing to a thriving, balanced aquarium ecosystem.

Let’s dive in and uncover the secrets to diagnosing and reviving your favorite plant. We’ll cover everything from identifying the type of browning to implementing the best practices for a full recovery.

First, Let’s Play Detective: Is It Algae or Is It Rot?

Before we can fix the problem, we need to correctly identify it. Not all brown is created equal in the aquarium world. The browning on your Anubias leaves is typically one of two things: a harmless layer of algae on the surface or a more serious sign of the plant itself decaying.

Figuring out which one you’re dealing with is the most critical first step in our anubias nana turning brown guide.

Identifying Brown Diatom Algae

If the brown on your Anubias looks like a dusty, dirty film that you could almost wipe off with your finger, you’re likely looking at brown diatom algae. This is especially common in tanks that are newly set up (less than six months old).

Here’s how to spot it:

  • Appearance: It looks like a fine, brown dust or a slimy coating on the leaves, glass, and substrate.
  • Texture: It wipes or scrapes off very easily. A gentle rub with your thumb should remove it.
  • Cause: Diatoms feed on silicates, which are often present in new tank substrate, sand, and tap water. They are a normal part of the “new tank syndrome” and usually go away on their own as the aquarium matures and beneficial bacteria become established.

Spotting True Plant Decay (Rot)

If the brown isn’t just on the leaf but is the leaf, you’re dealing with plant decay. This is a sign that the plant itself is unhealthy and needs immediate attention. This is one of the most common problems with anubias nana turning brown.

Here’s how to spot it:

  • Appearance: The leaves develop brown or yellow patches that become soft, mushy, and sometimes transparent.
  • Texture: The affected areas are part of the leaf tissue itself. They cannot be wiped off. The leaf may feel limp and fragile.
  • Progression: It often starts as a small spot and spreads, eventually causing the entire leaf to die and detach from the rhizome.

Once you’ve determined whether you’re fighting algae or rot, you can move on to pinpointing the cause.

The 5 Root Causes for Anubias Nana Turning Brown

Alright, now that you’re a pro at identifying the type of browning, let’s get to the “why.” Anubias are incredibly resilient, so when they start to fail, it’s usually due to one of a few very specific, and easily correctable, environmental issues.

Cause #1: The Rhizome is Buried (The #1 Rookie Mistake!)

If I could only give you one piece of advice, this would be it. The single biggest mistake aquarists make with Anubias is planting it like a typical stem plant.

Anubias have a thick, horizontal stem called a rhizome where the leaves and roots sprout from. This rhizome must be above the substrate (gravel or sand). If you bury it, it can’t breathe or exchange gases properly, and it will begin to suffocate and rot from the inside out. This rot will then spread to the leaves, turning them brown and mushy.

The Fix: Gently unearth your plant. Attach the rhizome to a piece of driftwood or a rock using super glue gel (aquarium-safe, cyanoacrylate) or cotton thread. The thin, stringy roots can go into the substrate, but the thick rhizome must stay exposed to the water column.

Cause #2: Lighting is Too Intense

Anubias evolved in shady, forested streams in Africa. They are true low-light plants. In our aquariums, we often blast them with high-intensity LED lights designed for more demanding species.

Too much light causes two problems:

  1. It encourages algae growth. Anubias are slow-growing, which makes their leaves a perfect landing pad for faster-growing algae (like brown diatoms or green spot algae) to take hold.
  2. It can directly stress the plant. In extreme cases, intense light can “burn” the leaves, causing them to yellow and eventually turn brown and decay.

The Fix: Move your Anubias to a shadier spot in the tank, perhaps under a larger plant or a piece of driftwood. Alternatively, reduce your lighting intensity or shorten your photoperiod (the amount of time the lights are on) to 6-8 hours per day.

Cause #3: Nutrient Imbalance

While Anubias are not heavy feeders, they still need access to essential nutrients from the water column. A deficiency or a major imbalance can cause leaves to struggle and turn brown.

  • Nutrient Deficiency: A common issue is a lack of potassium. This often shows up as tiny pinholes in the leaves, and the tissue around these holes can turn yellow or brown.
  • Nutrient Excess: High levels of phosphates and nitrates, often from overfeeding or infrequent water changes, don’t directly harm the Anubias but provide the perfect fuel for algae outbreaks on its slow-growing leaves.

The Fix: Start by ensuring a regular water change schedule (25-30% weekly) to reset nutrient levels. If you suspect a deficiency, consider dosing a comprehensive, low-tech liquid fertilizer once or twice a week. Look for one that contains potassium (K).

Cause #4: New Plant “Melt” or Acclimation Shock

Did you just add the plant to your tank within the last month? Plants are often grown emersed (out of water) at farms to speed up growth. When you submerge them in your aquarium, they have to transition and grow new, fully aquatic leaves.

During this process, it’s very common for the older, emersed-grown leaves to die off. This is called “melt.” They will turn yellow, then brown and mushy, as the plant reabsorbs their nutrients to fuel new growth. This is a natural process, not a sign that you’re doing something wrong!

The Fix: Patience! As long as the rhizome is firm and healthy, and you see signs of new, tiny green leaves emerging, your plant is just acclimating. Simply trim away the decaying leaves to keep your tank clean.

Cause #5: Physical Damage

Sometimes, the answer is the simplest one. Was the leaf damaged during transport or planting? Did a boisterous fish (like a pleco or cichlid) rasp on it or tear it?

Any physical wound to a leaf creates an entry point for bacteria and fungus. The plant will often “seal off” the damaged area, and that tissue will die and turn brown.

The Fix: There’s no way to heal a damaged leaf. The best course of action is to trim the damaged leaf off near the rhizome with clean, sharp scissors. This allows the plant to redirect its energy toward producing new, healthy growth.

Your Anubias Revival Plan: A Step-by-Step Care Guide

Feeling overwhelmed by the possibilities? Don’t be. Here is a simple, actionable plan. Follow these anubias nana turning brown best practices to get your plant back on track.

  1. Gently Clean the Leaves: If you’ve identified the issue as diatom algae, take the plant out during a water change and gently rub the leaves with your thumb or a soft-bristled toothbrush. It should come right off.
  2. Trim Away the Dead and Dying: Using sharp aquascaping scissors, snip off any leaves that are more than 50% brown, mushy, or covered in holes. Be decisive! Removing dying leaves allows the plant to focus its energy on new growth. Make the cut close to the rhizome without damaging it.
  3. Correct the Planting Method: This is non-negotiable. Check your Anubias right now. If the rhizome is even partially buried in the substrate, carefully lift it out. Use aquarium-safe glue or thread to attach it to a rock or piece of wood. This single step solves the problem for a majority of struggling Anubias owners.
  4. Assess and Adjust Your Lighting: Is your Anubias in a bright, open area? Move it into a corner or under an overhang. Reduce your lighting period to 7 hours a day and see if that helps reduce algae and stress over the next few weeks.
  5. Implement a Consistent Care Routine: Commit to a weekly water change and consider a weekly dose of an all-in-one liquid fertilizer. Consistency is key to a stable, healthy environment where plants can thrive.

Sustainable Tips for Preventing Brown Anubias in the Future

An ounce of prevention is worth a pound of cure. Once your plant is recovering, use these eco-friendly anubias nana turning brown prevention tips to keep it that way.

The “Set and Forget” Placement Strategy

Find a spot in your tank with low to moderate light and gentle water flow. Good flow delivers nutrients and prevents debris from settling on the leaves, which can block light and encourage algae. Once you find a good spot, try not to move it again. Anubias appreciate stability.

Embrace the Power of a “Clean-Up Crew”

Employing a natural, sustainable anubias nana turning brown solution is always best. Introduce a team of algae-eaters to do the housekeeping for you.

  • Nerite Snails: These are fantastic algae eaters and won’t reproduce in freshwater, so you don’t have to worry about a population explosion.
  • Otocinclus Catfish: A small school of these tiny catfish will diligently graze on brown diatoms and other soft algae without harming your plants.
  • Amano Shrimp: These are relentless workers, constantly picking at algae and leftover food.

Frequently Asked Questions About Anubias Nana Turning Brown

Can a brown Anubias leaf turn green again?

Unfortunately, no. Once a leaf’s tissue has started to decay and turn brown or yellow, it cannot heal itself or revert to green. The best course of action is to trim the damaged leaf off so the plant can divert its energy to new, healthy growth from the rhizome.

How quickly will I see improvement after making changes?

Patience is a virtue in the aquarium hobby, especially with slow-growing plants like Anubias. You won’t see overnight results. After correcting the issue (like unburying the rhizome), look for signs of new leaf buds emerging within 2-4 weeks. The existing healthy leaves should remain green and stop deteriorating.

Is it safe to use chemical algaecides on my Anubias?

I strongly advise against it. While some products claim to be plant-safe, Anubias can be sensitive. More importantly, algaecides only treat the symptom (the algae) and not the root cause (the imbalance of light and nutrients). Fixing the underlying issue is a much more effective and sustainable long-term solution.

My Anubias has dark green or black spots, not brown. What is that?

This is likely Green Spot Algae (GSA). It appears as hard, dark green, circular spots that are very difficult to scrape off. GSA is typically a sign of intense light and low phosphate levels. It’s very common on the leaves of slow-growing plants like Anubias. Reducing light intensity and ensuring a balanced fertilizer routine can help manage it.

Your Path to a Thriving, Green Anubias

Seeing your anubias nana turning brown can be disheartening, but it’s rarely a death sentence for this incredibly tough plant. More often than not, it’s a simple cry for help and a sign that a small adjustment is needed.

Remember the golden rules: keep the rhizome out of the substrate, provide low to moderate light, and maintain a stable, clean environment. By following the diagnostic steps and revival plan in this guide, you’ve armed yourself with the knowledge to solve the problem for good.

Don’t give up on your plant! With a little detective work and care, you can and will bring it back to its former glory. Now go forth and grow something beautiful!

Howard Parker
Latest posts by Howard Parker (see all)
Related posts
  • Anubias Nana Wrinkled Leaf – Your Complete Guide To Diagnosis And Lush
  • Anubias Nana Petite Dying: 7 Common Causes & How To Fix Them Fast