It can be quite alarming to see your aquarium plants turn white, especially if you’ve been thoroughly caring for them. But unfortunately, this is a pretty common occurrence and can happen due to several reasons.

Aquarium plants will turn white when optimal growing conditions are not met. Those conditions include light, pH, CO2 levels, and nutrients.

This article extensively discusses this problem and its solutions.

Underwater Nature Colour Ocean - LO-DESIGN / Pixabay
Source | LO-DESIGN / Pixabay

Reasons Why Your Aquarium Plants May Be Turning White

Aquarium plants, just like your fish, demand your care and attention. If you fail in that, they’ll begin to wither. The white discoloration you see on your plants is the first sign that something’s very wrong.

The factors behind the whitening of your aquarium plants include:

1. Inadequate Light

Aquarium Fish Water Aquatic Pets - OpenClipart-Vectors / Pixabay
Source | OpenClipart-Vectors / Pixabay

Plants need light to complete the process of photosynthesis. Aquarium plants are not an exemption. The type of light they get, the degree of brightness, and the length of exposure all play a role in maintaining plant health.

Photosynthesis occurs in the chloroplasts. The chlorophyll (the pigment responsible for the green color of plants) present in them absorbs sunlight to produce energy.

An absence of proper lighting means that the plants cannot absorb light or synthesize the dissolved CO2 available in the tank. As a result, they begin to lose their green color over time.

Another thing you need to watch out for is excess lighting in the aquarium. Too much lighting will cause the overgrowth of algae.

An algae bloom will starve the plants of scarce nutrients.

Thus, you must find the sweet spot where your plants are getting the right intensity and duration of exposure to light.

2. pH Imbalance

Another factor that affects the health of aquatic plants is the pH level of their water habitat. Different aquatic plants require different pH levels. For example, the Amazon sword plant thrives in an acidic environment, while other plants like Egeria prefer alkaline water.

Normally, the pH in the fish tank should be self-regulatory because the plants absorb and use the CO2 released by the fish. However, if the fish population outnumbers the plants, they’ll produce more CO2 than the plants can synthesize, thereby altering the pH of the water and making it acidic.

On the other hand, if the population of the plants far outnumbers the fish, they quickly use up all the CO2 in the water and make the pH more alkaline.

Consider the pH requirements of the plants you’re adding to the aquarium and the population of inhabitants. If there’s an imbalance in the pH levels, it could affect the general health of both your plants and fish.

3. Not Enough CO2 for Photosynthesis

The amount of CO2 in the aquarium alters the pH levels and affects the process of photosynthesis.

Terrestrial plants don’t need to worry about environmental carbon dioxide because the compound is always available in appropriate proportions.

They can extract as much as they need without running out.

However, underwater plants are not as lucky. CO2 is not readily available for use, and they depend heavily on other aquatic organisms, which release it as a respiration byproduct.

Without sufficient CO2, plants cannot undergo photosynthesis, and their health will deteriorate, causing discoloration.

4. Insufficient Nutrients

Aquarium Fishes Deco Nemo Dori - Michael_Luenen / Pixabay
Source | Michael_Luenen / Pixabay

Mineral nutrients are essential for your aquarium plants’ general health and pigmentation. If you have adjusted all other conditions in the tank (Lighting, pH, CO2), but your plants still look white, it could be because they lack vital micronutrients.

Here’s a list of the most important plant micronutrients and what their absence means for plant health:

  • Nitrogen: Aquatic plants growing without nitrogen will turn yellow or transparent. You’ll first notice these color changes at the tips before they spread to the rest of the plant. Eventually, the older affected leaves will fall off. Nitrogen deficiency is more noticeable in fish tanks with a small or no population of aquatic animals.
  • Iron: Iron deficiency causes the plant’s leaves to turn white or pale green.
  • Potassium: Plants that lack potassium start to have tiny holes, particularly around the edges and tips.
  • Calcium: Aquariums filled with soft water are very prone to calcium deficiencies. Affected plants not only become discolored, but their leaves also become stunted or twisted. Also, the leaf tips begin to wither.
  • Magnesium: Aquatic plants with magnesium deficiency turn white or transparent. They also tend to have dark veins that contrast the leaf color. As the leaves mature, the edges begin to droop.
  • Manganese: Some aquatic plants, like the Anubias Pinto, naturally have white patches. However, if this isn’t a natural characteristic of your aquatic plant and you begin to notice white or yellow patches, it could be because of a manganese deficiency.
  • Phosphorus: Some aquarium owners use a phosphate-absorbing pad to reduce the algae population in their tanks. However, those pads could seriously deplete the phosphorus levels in the water, affecting plant health in the process. Phosphorus deficient plants turn more yellow than white and have soggy brown patches. Instead of losing their color, some of them may also turn darker.

How Do You Stop Your Aquarium Plants From Turning White?

Fresh Aquarium Fish Aquarium Plant - suutapsinhvat0 / Pixabay
Source | suutapsinhvat0 / Pixabay

If you suspect that any of the factors highlighted above are at play, then here are some possible solutions:

1. Adjust The Lighting

Your aquarium plants need a regular day-night cycle. Avoid placing the tank under direct sunlight if you use artificial aquarium LED lights. Also, avoid using incandescent lights because they have weak penetration and will not evenly illuminate the aquarium.

Pay attention to the duration of plant exposure to light. You’ll want to avoid extremes, i.e., overexposure and underexposure.

To fix lighting issues, you might need to experiment a little. The amount of lighting adjustment required by your plants depends on the species and the level of lighting you’ve been exposing them to so far.

When using artificial lights in your tank, start with 0.25 watts per liter for low-lighting plants, 0.5 W/l for medium-lighting plants, and 0.8 W/l for highlighting plants.

This value is a general ballpark figure and may vary depending on your specific plant. You can research and experiment a little to determine the amount of lighting your aquatic plants need and change your bulbs and exposure time to match those needs.

2. Correct The pH Levels

Adjusting the pH levels of your aquarium can be a little challenging. First, you’ll need to do adequate research to determine the pH needs of all your aquatic organisms, both plants, and animals, before making any changes.

If you make any improper changes, you risk potentially damaging both. Balance is very important.

Generally, aquatic plants do not grow well in alkaline water (pH between 8-14), and pH levels reaching those figures could be responsible for your plants turning white.

The optimal pH for your plants may also depend on the type of ecosystem in the tank. However, generally, the pH in your tank should be as neutral as possible — between 5-8.5.

3. Increase The Level Of CO2

Fish Aquarium Fish Tank Marine - LopesTBM / Pixabay
Source | LopesTBM / Pixabay

If you suspect that the carbon dioxide level in your tank is quite low, you can take these steps to correct them:

● Check the CO2 Levels

You cannot know for sure that the absence of CO2 is responsible for your plants turning white unless you measure the level of CO2 in the tank. If you correct CO2 deficiency without first checking, you risk overloading your aquarium with carbon dioxide.

CO2 indicators are very useful for measuring carbon dioxide levels. Fill a drop checker with bromothymol blue solution and place it in the water tank.

When CO2 mixes with the solution, it produces carbonic acid, which lowers the pH of the solution and turns bromothymol blue to yellow. The yellow color indicates the presence of excess CO2. If the blue color turns green, it means the level of CO2 is optimal. However, if it remains unchanged, the CO2 levels are low.

During the day, the plants use up available CO2 and release oxygen into the environment. However, they use oxygen at night and release CO2 back into the habitat. Therefore, the best time to measure CO2 levels is at night when the plants are respiring.

● Add CO2 Artificially

Consider introducing CO2 artificially to the aquarium to increase its availability.

For example, you could deploy CO2 injection systems in the form of pressurized CO2 gas and liquid CO2.

However, turn them off at night to prevent oversaturation.

4. Add More Nutrients

Dissolved mineral nutrients are vital for the overall health of your aquatic plants.

Usually, your plants should get most of their nutrient requirements from the substrate (soil) and water. However, if you notice micronutrient deficiencies, you can use fertilizers to balance them.

A good fertilizer should contain all the essential micronutrients your plants need to survive, including Nitrogen, Calcium, Potassium, Magnesium, Phosphate, Iron, and Manganese.

This solution is all-encompassing, easier, and cheaper to use than buying individual mineral-based fertilizers.

The recommended levels of dissolved nutrients in a tank are:

  • Nitrogen: 10-20 mg/L
  • Calcium: 15 mg/L
  • Potassium: 0.15-1.0 mg/L
  • Magnesium: 10-15 mg/L
  • Phosphorus: 0.15-1.0 mg/L
  • Iron: 0.10 mg/L

You can test for these nutrients individually using dedicated test kits. If you have identified a particular deficiency causing your plants to go white, you can correct it using the following guide:

  • Nitrogen: Nitrogen is self-replenishing in a tank with an established nitrogen cycle. The best way to correct nitrogen deficiency is to introduce living organisms. Waste products produced by these animals contain nitrogen.
  • Calcium: Add crushed coral to soft water to introduce hardness and calcium slowly.
  • Potassium: Use a fertilizer that’s rich in potassium.
  • Magnesium: Most regular fertilizers contain magnesium. You can use them to correct magnesium deficiency in your aquarium.
  • Phosphorus: Introduce phosphorus-rich fertilizers to the tank to increase phosphorus levels.
  • Manganese: Any good nutrient-rich fertilizer should have micro quantities of manganese.
  • Iron: Use fertilizers specifically designed to correct iron deficiencies as general-purpose fertilizers never contain enough iron.

Note that even though you’ve introduced these nutrients into the aquarium ecosystem, it will take some time before you see results.

Plant recovery is not instantaneous and may take 1-2 weeks to begin to show. Therefore, constantly monitor your plants, observe any changes, and adjust your fertilization methods accordingly.

Early Signs Of Distress In Your Aquarium

It is often said that “Prevention is far better than cure.” Before your aquarium plants turn white, they may exhibit the following early signs of distress:

1. Changes in color

Color changes are early signs that your plants are in distress. For example, when the usually green leaves turn yellow or brown, check for the factors responsible and try to correct them as fast as you can.

Some plants may completely lose their color and become transparent, especially around the tips and edges.

2. Deformities

Deformed Leaves, Source | Reddit

When your plants suddenly begin to show some form of deformity, especially around the leaves, that could indicate that the conditions in the tank are no longer favorable for their growth.

Look out for when leaves suddenly wilt or become twisted, or a thick-stemmed plant becomes thin.

Poor lighting and nutrient deficiencies are the usual culprits behind plant deformities.

3. Slow Growth

Plants growing in less than optimal conditions become so stunted that their slow growth rate becomes drastically noticeable. Extreme ambient conditions like unstable pH levels, low lighting, and temperature may contribute to this.

Some plants may quickly recover on their own once the factors responsible are removed. However, for some, it may be too late to save them regardless of what you do.

4. Brittle Leaves

Some plants may become very brittle instead of exhibiting color changes. A simple touch can cause the leaves to fall apart.

If the leaves are also unusually tiny, it’s proof that the plant isn’t healthy and proper growth conditions have not been met in the tank.


Maintaining a thriving aquarium isn’t everyone’s cup of tea. You are constantly faced with challenges concerning the health and well-being of your aquatic plants and animals.

Plants turning white is one such common health issue. However, with proper diagnosis and appropriate remedies, you can always restore your aquarium’s health.

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