Why Are My Aquarium Plants Dying? 10 Causes and Fixes

Aquarium plants commonly die because they are adjusting to underwater growth, receiving too much or too little light, lacking nutrients or being planted incorrectly.

Brown, transparent or deteriorating leaves do not always mean the entire plant is dead. Healthy roots, rhizomes and fresh new growth are often better indicators of whether an aquarium plant can recover.

At Simply Fish, the most common plant problems customers ask us about are:

• Plants that appear to be dying
• Holes developing in the leaves
• Algae growing over the plants
• Plants that are not producing healthy new growth

The good news is that most aquarium-plant problems can be corrected once you identify the actual cause.

Quick aquarium-plant problem guide

Symptom	Likely cause
New plant losing its original leaves	Transitioning from above-water to underwater growth
Yellow or pale leaves	Possible nutrient deficiency
Pinholes or damaged leaf edges	Often a nutrient deficiency or physical damage
Transparent or dissolving leaves	Plant melt, stress or insufficient nutrients
Algae covering slow-growing leaves	Too much light, unhealthy plant growth or an imbalance
Plant keeps floating out of the substrate	Incorrect planting or insufficient root development
Anubias or Java fern base turning soft	Rhizome may have been buried
Tall, thin or stretched growth	Insufficient light
Plants grow but algae spreads rapidly	Light may be too strong or left on too long
Root-feeding plants struggle in gravel	Insufficient nutrition around the roots

1. Your new aquarium plants may be transitioning

One of the most common misunderstandings in the aquarium industry is that a newly purchased plant is dying when it is actually adjusting to life underwater.

Many aquarium plants supplied to stores are commercially grown above water, or emersed.

This is common because there is no practical, cost-effective way to produce enough aquarium plants entirely underwater to meet industry demand. Growing plants emersed also allows commercial growers to produce healthy plants efficiently before supplying aquarium stores.

Once these plants are placed underwater, their existing leaves may no longer be perfectly suited to submerged growth.

The plant may allow its original leaves to deteriorate while producing an entirely new form of underwater growth.

This process is commonly called plant melt.

What plant transition can look like

During the transition, you may notice:

• Older leaves turning transparent
• Leaves becoming soft
• Sections of the plant breaking down
• Leaves changing shape or colour
• The plant temporarily looking worse after being added

This does not necessarily mean the roots or the entire plant are dead.

At Simply Fish, we regularly encourage customers to leave newly planted aquarium plants in place and watch for fresh growth before pulling them out.

It is extremely common for someone to assume a plant has died, remove it and throw it away just before it would have started producing healthy submerged leaves.

What you should do

Remove leaves that have completely deteriorated, but leave the healthy roots, stems, crown or rhizome in place.

Watch for:

• New shoots
• New roots
• Fresh leaves
• Firm stems
• A healthy crown or rhizome

New growth is a much better indicator of plant health than the condition of leaves that were already present when the plant was purchased.

2. Your aquarium light may be too strong

People often assume more light will always produce better plant growth.

That is not how planted aquariums work.

A powerful aquarium light can produce excellent plant growth when the plants have access to suitable nutrients and carbon dioxide. However, excessive light can also expose weaknesses in the aquarium and encourage rapid algae growth.

This is one of the most common issues we see with planted aquariums.

Some aquarium lighting systems are considerably more powerful than beginners realise. We particularly find that the standard lights on some Juwel Rio aquariums can be overpowering for a basic planted setup.

This can result in:

• Algae forming on plant leaves
• Algae growing on hardscape and glass
• Slow-growing plants becoming covered
• Plants struggling to compete with algae
• Customers increasing fertiliser unnecessarily
• An aquarium that becomes difficult to balance

How long should aquarium lights stay on?

For many beginner planted aquariums, starting with approximately six to eight hours of light per day is reasonable.

Use a timer or controllable light so the schedule remains consistent.

Do not leave the light on from early morning until bedtime simply because someone is home and wants to see the aquarium.

The plants do not benefit from unlimited light.

If algae is already spreading, reducing the lighting period or intensity is often more useful than adding another algae treatment.

3. Your aquarium light may be difficult to control

The issue with some standard aquarium lights is not necessarily that they are poor-quality lights.

The problem is that they may not give the owner enough control.

A light can be capable of growing aquarium plants while still being too intense for the particular plants, nutrient levels and CO₂ available in the tank.

For Juwel aquarium owners experiencing repeated lighting and algae problems, we often recommend considering a Chihiros WRGB Universal.

The WRGB Universal can fit directly into compatible Juwel aquariums as a replacement lighting option. Its output and colour channels can be controlled through the My Chihiros app, allowing the aquarium owner to adjust the lighting rather than being stuck with one fixed output.

The WRGB Universal has a higher price tag than basic aquarium lighting, but it can solve a number of common lighting problems while making both plants and fish look considerably better.

It is currently our second-most-popular aquarium-lighting range in store.

A premium light is not automatically a cure for dying aquarium plants. The advantage is the control it gives you over:

• Light intensity
• Daily lighting duration
• Colour balance
• Sunrise and sunset schedules
• How the aquarium looks throughout the day

Being able to reduce the intensity is often just as useful as being able to produce more light.

Shop Chihiros WRGB Universal aquarium lights

4. Your plants may not be receiving enough light

Although too much lighting is common, plants can also struggle when they do not receive enough.

Insufficient lighting can cause:

• Slow or stopped growth
• Tall, stretched stems
• Large gaps between leaves
• Lower leaves dying
• Pale growth
• Plants leaning heavily toward the light
• Carpeting plants growing upwards instead of spreading

Different aquarium plants have different lighting requirements.

Anubias and Java fern can usually tolerate relatively modest lighting. More demanding red plants and carpeting plants generally require significantly stronger and better-controlled lighting.

This is why selecting plants that match your equipment is more important than choosing plants purely by appearance.

For an easier starting point, read our guide to the 10 Best Easy Aquarium Plants for Beginners

5. Your plants may be lacking nutrients

Aquarium plants need more than water and light.

They require a range of nutrients to build new leaves, roots and stems. Fish food and fish waste can contribute nutrients, but they may not provide everything the plants require in the correct amounts.

Possible signs of a nutrient deficiency include:

• Yellow leaves
• Pale new growth
• Holes in leaves
• Weak or thin stems
• Damaged leaf edges
• Poor root development
• Leaves falling away
• Very slow growth

It is difficult to diagnose a specific nutrient deficiency from one symptom alone. Several deficiencies, plant-transition issues and physical damage can look similar.

For most beginner aquariums, the sensible approach is to use a reputable, balanced fertilising system rather than attempting to diagnose and separately dose every individual nutrient.

Our Seachem Flourish fertiliser guide explains the different products in the Flourish range and when each one may be useful.

6. Plants with holes may need more nutrition

Holes in aquarium-plant leaves are one of the most common problems customers bring to us.

Small pinholes can gradually expand, leaving damaged patches or broken leaf edges. This is often associated with insufficient plant nutrition, although it can also be caused by:

• Fish or snails damaging leaves
• Leaves deteriorating during plant transition
• Old leaves naturally breaking down
• Physical damage during transport or maintenance
• Poor overall plant growth

Do not assume that every hole is caused by a fish eating the plant.

Check whether the holes are appearing primarily on old leaves or new leaves, whether several plant species are affected, and whether the plant is producing healthy new growth.

Old, damaged leaves will generally not repair themselves. The goal is to correct the underlying issue so the plant produces stronger replacement leaves.

7. Root-feeding plants may be starving in the substrate

Some aquarium plants take a significant amount of their nutrition through their roots.

Examples include:

• Amazon swords
• Cryptocoryne
• Vallisneria
• Dwarf sagittaria
• Many larger rooted plants

These plants may struggle when planted in plain gravel or sand with no additional root fertiliser.

A liquid fertiliser primarily adds nutrients to the water column. It may not provide enough concentrated nutrition around the roots of a heavy root-feeding plant.

For these plants, we commonly recommend one of three options.

Seachem Flourish Tabs

Seachem Flourish Tabs are placed into the substrate near the plant roots, where they provide slow-release nutrition directly to the root zone.

They are a straightforward option for common planted aquariums and work well underneath heavy root feeders.

Shop Seachem Flourish Tabs

2HR Aquarist APT Jazz

APT Jazz is another root-fertiliser option we recommend for planted aquariums.

It can be inserted beneath rooted plants to replenish nutrition around the substrate.

Shop 2HR Aquarist APT Jazz

JBL The 7 Balls

For customers wanting a clay-based root fertiliser, we often recommend JBL The 7 Balls.

The balls are placed into the substrate around root-feeding plants and provide a localised source of nutrition.

Shop JBL The 7 Balls

You do not need to use all three products together. Choose one appropriate root-fertilising option and follow its instructions.

8. Anubias or Java fern may be planted incorrectly

Anubias and Java fern are regularly recommended as easy beginner aquarium plants.

They are hardy, tolerate relatively low light and do not require nutrient-rich planted substrate.

However, they are also among the plants we most commonly see planted incorrectly.

Both Anubias and Java fern grow from a thick horizontal structure called a rhizome.

The roots can grow into the substrate or attach to aquarium hardscape, but the rhizome should not be completely buried.

When the rhizome is buried under gravel, sand or aquasoil, it can begin to rot.

How to plant Anubias and Java fern correctly

Attach the plant to:

• Driftwood
• Aquarium rocks
• Decorations
• Other suitable hardscape

You can secure it using:

• Aquarium-safe glue
• Cotton thread
• Fishing line
• A suitable plant weight or crevice

The roots will gradually attach themselves to the surface.

If you want the plant to appear as though it is growing from the substrate, position the roots in or near the gravel while keeping the rhizome exposed above it.

Signs of a rotting rhizome can include:

• A soft or mushy base
• Leaves separating from the rhizome
• A darkened rhizome
• Several leaves deteriorating from the base
• A bad smell when the plant is removed

Correcting the planting early may allow healthy sections of the rhizome to survive.

9. Algae may be covering your plant leaves

Algae growing on aquarium plants does not always mean the plant itself is unhealthy.

However, algae can become a serious problem when it covers enough of the leaf surface to restrict the light available to the plant.

Slow-growing species such as Anubias are particularly vulnerable because their leaves remain in place for a long time.

Common causes of algae growing on plants include:

• Excessive light
• Lighting left on too long
• Plants not growing strongly enough to use available nutrients
• Unstable CO₂ levels
• Accumulated organic waste
• Poor water circulation
• An aquarium that has not yet matured
• Slow-growing plants positioned directly beneath strong lighting

The answer is rarely to simply add more fertiliser, turn the lighting up or buy an algae-eating fish without addressing the cause.

What to do about algae-covered plants

Start by:

1. Reducing excessive lighting
2. Keeping a consistent lighting schedule
3. Removing badly affected leaves
4. Cleaning manageable algae from tougher leaves
5. Improving general aquarium maintenance
6. Checking plant nutrition
7. Confirming that water circulation reaches planted areas
8. Encouraging healthy new plant growth

For stubborn black beard algae, read our guide to removing black beard algae from an aquarium

10. Your fish may be damaging the plants

Not every damaged aquarium plant has a lighting or nutrient problem.

Some fish may:

• Eat soft leaves
• Dig around roots
• Uproot newly planted stems
• Tear leaves while feeding
• Move plants while rearranging substrate

Goldfish, large cichlids and some herbivorous fish can be particularly difficult to keep with delicate planted layouts.

Snails may also be blamed for plant damage, but many common aquarium snails are more interested in deteriorating plant matter and algae than healthy leaves.

Before deciding that an animal is eating the plants, check:

• Whether the damaged tissue was already dying
• Whether the damage appears overnight
• Whether bite marks are visible
• Whether the plant is being uprooted
• Whether only softer species are affected
• Whether the fish species is known to eat or disturb plants

Choosing tougher plants such as Anubias or Java fern can help in aquariums containing fish that are hard on vegetation.

11. Your substrate may not suit the plants

Aquarium plants can grow in many different substrates, including:

• Aquasoil
• Gravel
• Sand
• Clay-based planted substrates
• Nutrient-rich commercial substrates

However, the substrate affects how easily plants root and how much nutrition is available around them.

Plain gravel and sand can still be used successfully, but they contain little or no plant nutrition unless nutrients accumulate naturally or are added using root fertilisers.

Very coarse gravel can make it difficult for smaller plants to root securely. Extremely compacted substrate can also interfere with healthy root development.

If a plant repeatedly floats out of the substrate:

• Plant it more deeply without burying the crown
• Use planting tweezers
• Trim damaged roots rather than folding them
• Add a suitable plant weight temporarily
• Place small stones around the base
• Allow time for new roots to establish

Do not bury plants so deeply that the crown, rhizome or lower stems begin rotting.

12. Your aquarium may lack carbon dioxide

All aquarium plants use carbon dioxide.

A basic aquarium receives some CO₂ naturally through fish respiration, biological activity and gas exchange. Many hardy plants can grow without an injected CO₂ system.

However, the amount naturally available is limited.

When a tank has powerful lighting but very little available CO₂, plants may be unable to use all the light they receive efficiently. This can contribute to weak plant growth and persistent algae.

This does not mean every beginner aquarium needs injected CO₂.

A better first approach is usually to:

• Choose easy plants
• Reduce excessive lighting
• Use suitable fertilisation
• Maintain consistent conditions
• Avoid chasing extremely fast growth

Injected CO₂ becomes more useful when you want to grow demanding carpeting plants, produce intense red colouration or run a high-light aquascape.

How to save dying aquarium plants

Avoid changing everything at once.

When someone changes the light, fertiliser, water parameters, substrate and planting position at the same time, it becomes impossible to identify the original problem or determine what fixed it.

Use this process instead.

Step 1: Look for healthy plant tissue

Check the roots, stems, crown and rhizome.

Firm tissue and fresh growth suggest the plant may still recover.

Step 2: Remove completely dead leaves

Damaged leaves will not usually return to their original condition.

Remove leaves that are completely soft, transparent or deteriorating so the plant can focus on healthy growth.

Do not remove every leaf unless they are genuinely dead.

Step 3: Check how the plant is planted

Make sure:

• Anubias and Java fern rhizomes are exposed
• Plant crowns are not buried
• Stem plants are deep enough to remain secure
• Rooted plants have space to develop roots

Step 4: Review your lighting

Check:

• How many hours the light runs
• Whether the intensity can be adjusted
• Whether the plant is positioned directly beneath the strongest area
• Whether algae increased after changing the lighting
• Whether the plant species actually needs strong light

Step 5: Review plant nutrition

Determine whether the plant feeds mainly through:

• The water column
• Its roots
• Both

Use a suitable liquid fertiliser or root fertiliser rather than adding random treatments.

Step 6: Give the plant time

Aquarium plants do not recover overnight.

Leave the plant in a stable position and watch the newest growth. The new leaves show how the plant is responding to its current conditions.

Common mistakes when treating dying aquarium plants

Pulling plants out too early

A melting plant may still have healthy roots or a healthy rhizome.

Give it time to produce submerged growth before deciding it is dead.

Adding more light

More light can make algae worse when the actual problem is a shortage of nutrients or CO₂.

Adding every fertiliser available

Adding several products without understanding them can make troubleshooting more difficult.

Use a clear fertilising routine.

Expecting old leaves to recover

Leaves with holes, severe yellowing or extensive melting normally will not repair themselves.

Judge success by the quality of new growth.

Buying an algae eater as the only solution

Algae eaters can help manage certain types of algae, but they do not correct excessive lighting or poor plant growth.

Moving plants repeatedly

Repeatedly uprooting plants damages their developing roots and forces them to adjust again.

Frequently asked questions

Should I remove dying leaves from aquarium plants?

Remove leaves that are completely dead, transparent or deteriorating.

Partially damaged leaves can sometimes remain temporarily if they still contain healthy green tissue, but old damage will not repair itself.

Avoid removing so many leaves that the plant has no healthy tissue remaining.

Why are my new aquarium plants melting?

Many commercially produced aquarium plants are grown above water.

When placed underwater, their original leaves may deteriorate while the plant produces new submerged leaves. This is a common transition and does not necessarily mean the plant has died.

Why do my aquarium plants have holes?

Holes can result from insufficient nutrients, physical damage, deteriorating older leaves or animals damaging the plant.

Check whether healthy new leaves are also developing holes. Persistent damage on new growth is more concerning than holes limited to old leaves.

Why are my aquarium plants turning brown?

Brown leaves may be caused by plant transition, dying older growth, insufficient light, poor nutrition or algae and debris coating the leaves.

Look closely to determine whether the leaf tissue itself is brown or whether something is growing on its surface.

Can too much light kill aquarium plants?

Excessive light does not necessarily kill a plant directly, but it can create conditions where algae grows faster than the plants can compete.

A powerful light must be balanced with suitable nutrients, available CO₂ and healthy plant growth.

How long should I wait before removing a melting plant?

There is no exact timeframe for every species.

As long as the roots, crown or rhizome remain healthy, leave the plant in place and watch for new growth. Recovery may take several weeks depending on the plant and aquarium conditions.

Do aquarium plants need root tabs?

Root tabs are particularly useful for heavy root-feeding plants growing in plain gravel or sand.

Anubias and Java fern generally receive more of their nutrition from the water and usually do not need root tabs placed directly beneath them.

Do all aquarium plants need fertiliser?

All aquarium plants require nutrients, but the amount and delivery method vary.

Some may obtain enough nutrition from fish waste and the aquarium environment, while more heavily planted tanks often benefit from a consistent fertilising routine.

Give your plants time to recover

Dying aquarium plants are usually a symptom of an underlying issue rather than a mystery.

The most common causes are:

• Transitioning from emersed to submerged growth
• Excessive or insufficient lighting
• Poor nutrient availability
• Lack of root fertilisation
• Incorrect planting
• Algae covering the leaves
• Unsuitable fish or substrate
• Limited available CO₂

Start by checking the newest growth, how the plant is positioned and whether your lighting is appropriate.

Most importantly, do not remove a plant simply because its original leaves are deteriorating. Across the aquarium industry, many plants are grown above water and need time to develop their submerged form.

A plant that appears to be dying today may begin producing healthy underwater leaves once it has completed that transition.

Browse our live aquarium plants, explore the aquarium plant fertiliser range, or visit the Simply Fish team in Christchurch for help identifying what your plants need.