Aquarium Plant Leaves Curling – Causes and Solutions

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Aquarium plants require specific conditions to thrive, and while they’re quite hardy in general, drastic changes in water parameters can hurt them. Your plant will exhibit specific signs depending on the problem it’s dealing with.

Today, we will discuss curled leaves and the potential causes behind them. Before doing so, it’s worth mentioning that aquatic plants will often display different physical changes to the same triggers. In other words, one plant could display yellowing or transparent leaves due to poor lighting, while another may showcase curling or browning leaves for the exact same reason.

Other problems will cause pretty much the same symptoms in almost all cases. This is true for potassium deficiency, for instance, which always causes the plant’s leaves to exhibit yellow holes.

As you can see, the situation can get confusing fast. So, let’s un-confuse it!

What Causes Aquarium Plant Leaves to Curl?

If you notice your aquarium plant’s leaves curling up gradually by the day, consider the following:

Insufficient Light

Plants require 3 primary assets to remain healthy and thrive: a light source, CO2, and adequate nutrients. They also need water, a proper substrate, a safe habitat, etc. But those 3 are vital components which form the foundation of any healthy habitat. Light is probably the most important among those.

Aquatic plants use light in combination to CO2 and adequate nutrients to perform photosynthesis. This is a process that produces oxygen and synthesizes various chemicals from the surrounding environment. The problem with indoor tanks is that plants often live in subpar lighting conditions, which will impact their growth rate and overall health status.

When we talk about improper lighting, we talk about 2 core things:

Improper Light Intensity

If the environmental light is too weak, the plant won’t be able to perform adequate photosynthesis. There’s a common misconception that the plant’s physiological functioning varies between day and night, but that’s not quite true. It actually varies between high-light and low-light conditions. In other words, plants consume CO2 and produce oxygen in high-light conditions and consume oxygen and produce CO2 in low-light conditions.

And the notion of ‘low-light conditions’ doesn’t refer to nighttime-only but daytime conditions with insufficient lighting as well. Cloudy days will also disrupt the plant’s internal processes, influencing its physiological behavior. So, provide plants with 20-40 lumens per liter or more, depending on the species.

Different plant species require different light levels, and some will thrive in low-light conditions. Others demand brighter lights which also puts your tank at risk of experiencing algae bloom. Not to mention, excessive light intensity is also responsible for curled leaves.

So, finding a balance in this sense is vital.

Insufficient Light

Plants need a balanced light/dark cycle to thrive. On average, aquarium plants require approximately 8-10 hours of light per day to perform proper photosynthesis. The lack of sufficient light will cause the plant to die via suffocation and starvation.

Just as with the light intensity, different plant species also showcase different requirements in terms of light duration. Some may do fine with 8 hours, while others may need 10-12 hours of light. Make sure you understand your plant’s needs to provide it with optimal living parameters.

CO2 Content

Plants require CO2 as part of their breathing process. Without it, they cannot perform photosynthesis, no matter how much light they’re getting. Fortunately, a well-cycled tank will produce CO2 naturally via fish and bacterial breathing. Unfortunately, the available CO2 is often insufficient for your plants’ needs.

It really depends on how many aquatic plants you have, how large the tank is, how many fish species there are, etc. If the CO2 level drops too low, your plants will experience breathing difficulties, and the risk of algae bloom will also be higher. Algae thrive in low-CO2 environments.

To counter this problem and help your plants along the way, consider CO2 injections. Keeping the CO2 within the ideal parameters is key to preventing curled leaves and plant death. Just don’t go overboard with it. Fish have no use for CO2 since it causes breathing difficulties. Be mindful about your fish’s needs, especially if you’re housing more sensitive species.

Nutrient Deficiency

Aquatic plants extract a variety of nutrients from their environment. These include magnesium, potassium, calcium, manganese, iron, etc. These are readily available in the wild in an open system but can be difficult to balance in a closed system. Typically, plants will exhibit different signs of nutrient deficiency based on the nutrient they’re lacking.

If they show curled leaves, consider a calcium deficiency, although boron and magnesium also cause this phenomenon. If your plants exhibit symptoms of nutrient deficiency, this is a sign that you need to consider fertilization as a nutritional strategy. Especially if you don’t have enriched soil to provide your plants with adequate nutrition.

You should use root tabs for rooted plants and liquid fertilizers for floating ones. Just remember that excess liquid fertilization promotes algae bloom. So, only use whatever’s necessary for your plants, but don’t overdo it.

Plant Differences

I will admit that this point is a bit more confusing than the rest, but it’s worth mentioning. The idea is that not all plants require the same environmental conditions or amount of nutrients as others. Some demand more light, others need less nutrients than others, with the excess nutrients causing them distress, etc.

These differences will cause the plants to react differently to the stimulus around them. If your plant doesn’t need too much light, but they’re getting it, either way, the plant may exhibit signs of stress. The curled leaves are pretty good indicators in this sense.

The same happens with variations in temperature, water nutrients, and water quality. Some plant species are more sensitive and delicate than others and will show it.

New Tank Syndrome

The New Tank Syndrome typically describes the behavior of fish and other aquatic life forms being forced into a new environment. It rarely describes plant behavior, but it should. Plants also experience some form of New Tank Syndrome, as they require time to adapt to their new habitat.

The familiarization process involves the plant growing its roots and anchoring itself in the substrate. This may take some time, usually around 2-3 weeks, depending on the plant and the available conditions. So, your plant may showcase curled leaves and even some paleness as it becomes accustomed to its new conditions.

Fortunately, this is reversible, as the plant will return to its full glory shortly. That said, you should always check water parameters to ensure you’ve identified the cause accurately. You don’t want to be wrong about it since it can make the difference between life and death for your plant.

What to do With Curled Aquarium Plant Leaves?

If your plant exhibits curled leaves, you have 2 options:

  • Wait it out – Curled leaves are not necessarily dead. The most obvious sign of dying or dead leaves is the coloring. Dying leaves will lose their chlorophyll and turn yellow and brown in the final stages. They will then fall off, at which point you need to remove them from the environment. If they’re curled but retain their coloring, just wait it out. Identify the cause responsible for the effect, take appropriate measures, and give the plant some time to recover. It generally will.
  • Remove them – This is necessary when all other measures have failed. Not only are the leaves curled, but they now appear to lose their coloring as well. They may even show rugged margins, tiny holes in their structure, and yellowing or browning around the edges. This is a sign that they’re dying, and there’s nothing you can do about it. Removing them is the best option.

You shouldn’t jump to the second option without giving first option some time first. Plants will bounce back once the environmental conditions have been restored, so don’t jump to conclusions without seeing the bigger picture.


Aquarium plants will thrive under the right conditions. However, since not all aquatic conditions are ideal, it’s natural for your plants to exhibit signs of stress once in a while. Don’t panic, assess the situation objectively, and look for a reliable solution. Most plants will recover fast, provided the situation isn’t severe or too advanced.

If it is and your plants seem to be beyond saving, remove them from the environment. Dead plants represent a hotspot of ammonia production since they now represent dead and decaying matter. Replace them with a new set of live plants and apply what you’ve learned to accommodate them better than the last ones.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.
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