Why are your aquarium plants turning brown and transparent? 

If your plants are turning a brown color, it’s possible they’re not receiving proper care. 

But all is not lost! Knowledge is power when your plants turn brown or go more transparent.

Improper care or tank conditions may cause aquarium plants to turn brown. For example, inadequate lighting and lack of nutrients may have this effect. While this is alarming for many new aquarists, there are ways to bring your plants back. 

Learn how to care for aquarium plants, and get ready for an aquascaping adventure.

Why are your aquarium plants turning brown? 

There are a variety of common reasons why the plants in your aquarium are turning brown:

• Poor planting technique
• Improper water parameters or water quality
• Too much or too little light
• Lack of fertilization
• Lack of nutrients
• Type of plant

Let’s take a more detailed look at each of these reasons.

Planting Technique

It’s crucial to use proper planting techniques when adding plants to your fish tank. 

The technique you use will depend on the type of plant(s) you get:

• Stem plants (anacharis, bacopa): Plant the stems 2 to 3″ inches deep in the gravel or substrate. Make sure they’re not too close together. Also, weigh them if needed using special plant weights. 
• Rhizome plants (anubias, java fern): These plants have thick stems which grow leaves. To plant them, find a suitable anchor point (such as a log) and attach it to the point using super glue. The plant will eventually wrap itself around the anchor point. Another option is to secure the roots between some aquarium rocks. 
• Sword plants (Amazon sword, red fern sword): For sword plants, bury the roots deep in the substrate. But ensure you don’t cover the crown back up, as this will prevent new leaves from growing. 
• Crypt plants (Cryptocoryne spiralis, Cryptocoryne parva): Bury the roots deep in the substrate. Be aware: its leaves might fall off. This means it’s losing its old leaves to grow new ones better suited to its environment. 
• Moss (Java moss, Christmas moss): With moss, you have two options. Either attach it to an anchor point with super glue or let it float freely.

When planting, ensure you don’t crowd any plants too close to each other. Overcrowding makes it more difficult for individual plants to thrive. 

Also, locate the plants so they receive enough light and oxygen. This is crucial because plants depend on both to flourish. 

Water Quality

The water conditions in your aquarium are vital to your plant’s health.

Ensure your aquarium water falls within optimal parameters for your plant species. This includes achieving the ideal water temperatures, pH, and hardness level. 

The tank water should also contain essential nutrients for the plant. We recommend adding liquid fertilizer to the water, including various nutrients.

Also, ensure your plants receive enough nitrates. Nitrates play a key role in growing healthy plants, allowing for greener, fuller leaves.

Finally, the water should have low nitrite levels.

Nitrites like ammonia may cause poor plant growth, browning, or dead plants. Achieve low nitrite levels by performing frequent water changes. Also, remove uneaten betta food from the tank each day.

Note: To achieve the best possible water quality, buy an aquarium water testing kit like this one.

It will help you keep tabs on water conditions anytime, allowing you to take timely action. 

Here are some different ways to create healthy aquatic environments: 

• Perform frequent water changes 
• Add liquid fertilizer to the tank water
• Add water conditioner 
• Frequently check water conditions

Lighting Conditions

Aquarium plants need sufficient lighting to thrive. There are a few reasons for this: 

• Proper lighting helps their photosynthesis process. 
• Too little lighting can cause brown algae to form, harming the tank water and the plant. 

The key is to ensure the lighting conditions align with the plant species’ needs.

Opt for lighting mechanisms that also allow you to program light-dark cycles. This will help the plants stay in sync with their circadian rhythms, keeping them vibrant and well. 

Types of Aquarium Lighting Solutions

Lighting is a critical component of your planted aquarium environment. This makes it imperative you consider the duration and intensity of light.

Your aquarium plants will enjoy a lighting solution with a day-night cycle. It will provide them with a more natural lighting experience, encouraging growth. Read up on the lighting needs of the plant species. Then, set your aquarium lighting cycle accordingly. 

If you give your plants too much light, it can cause issues such as excessive algae growth or brown spots. Too little light results in diminished plant growth and less green color. 

There are a few different types of aquarium lighting solutions to consider:

• Standard fluorescent: This is the most popular aquarium lighting type. It’s affordable, energy-efficient, and provides ample lighting for most aquariums. However, their light output may be inadequate for planted aquariums. 
• Compact fluorescent: This style is similar to standard fluorescent lighting. The difference is: compact fluorescent lights are much smaller. They also produce more light. However, this type produces some heat, which may be a fire hazard. 
• LED: Another popular option, LED lights offer ample lighting without producing much heat. People love this type for its low energy use, affordability, and convenience. 
• Metal halide: This is the best aquarium lighting solution for large tanks. It produces a lot of light and heat. The excess heat means you’ll need to take precautions, such as installing a fan nearby to cool it off. 

Ideal Light Intensity and Duration for Healthy Plant Growth

The exact light intensity and duration your plants need will depend on the species. 

Determining the appropriate light intensity may involve some experimenting. Many aquarium keepers choose to give new plants a lower level of light intensity.

This allows the plants some time to adjust to their new environment. It also helps prevent algae takeover in the plants’ early days. 

Once the plants have adjusted, experiment with different light intensity settings.

As for light duration, most aquatic plants thrive on anywhere from eight to ten hours of light. We recommend opting for a lighting solution offering a day-night cycle or an on-off timer.

This way, your plants will receive a more natural (and automated) duration of light. 

Tips for Preventing Browning or Yellowing Plants

Giving your plants too much or too little light can result in various issues. The best way to avoid browning or yellowing plants is to provide just enough lighting:

• Research the plant species you want and determine its specific needs.
• Buy an aquarium lighting solution with a day-night cycle or auto on-off function.
• Ensure the light does not produce too much heat. 
• Adjust the lighting intensity or duration if you notice issues with plant health. 

Find more tips in our guide to yellowing aquarium plants. 

Fertilization

Your aquarium plants need a variety of essential nutrients to thrive. Luckily, there are liquid fertilizers and other supplemental products available to help. 

When shopping for a good fertilizer, look for extra nitrogen and CO2 products. Here are some more key nutrients to check for: 

• Nitrogen
• Phosphorus
• Potassium
• Manganese
• Copper
• Zinc
• Iron
• Magnesium
• Calcium

Ensure the fertilizer you buy contains a balanced combination of these nutrients. 

Also, keep the pH and chemical balance of the water in mind while adding fertilizer. 

Types of Fertilizers

There are three primary types of plant fertilizers available: 

• Liquid: This type of fertilizer goes into the tank water. It’s ideal for plants to grow without substrate and absorb nutrients from the water.
• Tablet: Tablets also go right in the aquarium water. They dissolve to release key nutrients into the water for the plants to absorb. 
• Substrate: Some plants only get nutrients from soil or substrate. This is where substrate fertilizer comes into play. Just follow the directions on the packaging!

Consider your plant species before buying any fertilizer solution. This will help you choose the right type and nutrient contents. 

Proper Dosing and Frequency

The correct dosing and frequency for fertilization will depend on two factors: 

1. The plant species you have
2. The exact fertilizer you’re using

We recommend following the directions on the fertilizer’s packaging. This way, you use the product as the manufacturer intended for the best results. 

How To Choose the Right Fertilizer

When looking for a quality fertilizer for your plants, consider these factors: 

• Nutrient content: Always check the nutrient content of a fertilizer before buying it. Aquatic plants have specific nutrition needs, and not all fertilizers provide them. Ensure the product has all the essential nutrients, including extra CO2 and nitrogen.
• Type: The type of fertilizer you use (liquid, tablet, substrate) will depend on the type(s) of plants you have. Some plants get nutrients from the water, and others get them from the soil/substrate.
• Brand: Only buy from reputable brands, as they tend to offer better quality products. Do your research and read customer reviews before buying anything.

CO2 Supplementation

CO2 is an especially important nutrient for aquarium plants. It allows them to perform photosynthesis by pulling it from the water and turning it into oxygen.

Adequate CO2 levels help plants stay green and vibrant. 

Supplementing your tank with CO2 is a great way to increase plant growth. It also allows for more efficient photosynthesis. This means the plants will be greener and lusher. 

There are a few different methods for increasing CO2 levels in the aquarium: 

1. Use an injector system: This method involves using a device to inject CO2 into the water. This method is convenient and effective. However, it’s also rather expensive and requires lots of maintenance. 
2. Cycle your lighting: Your lighting cycle can affect CO2 levels in the water. Giving your plants some “dark” time stops photosynthesis, allowing CO2 levels to rise for a bit.  
3. Get slow-growing plants: Consider opting for slow-growing plants. They will take less CO2 from the water each day than other plants, keeping levels more balanced. 
4. Reduce the water current: Water movement increases oxygen levels. This means reducing the current helps with CO2 production. This is a simple and affordable fix, but it might mean investing in a new low-flow filter, for example. 

Plant Species

There are several different species of aquatic plants.

When choosing plants for your aquarium, consider their care needs. If you’re a beginner, we recommend starting with easier plants. This is because the more difficult a plant is to care for, the more likely it will brown or yellow. 

Here are some of the most common, easy-to-care-for freshwater plants: 

Anubias 

• Type: Rhizome
• Care Level: Easy
• Growth Rate: Slow
• Lighting: Low to moderate
• Nutrients: From substrate

Amazon Frogbit

• Type: Floating
• Care Level: Easy
• Growth Rate: Fast
• Lighting: Medium
• Nutrients: From water

Java Moss

• Type: Moss
• Care Level: Easy
• Growth Rate: Slow
• Lighting: Low to medium
• Nutrients: Water

Water Sprite

• Type: Stem
• Care Level: Easy
• Growth Rate: Slow to moderate
• Lighting: Low to moderate
• Nutrients: Water

Cryptocoryne wendtii

• Type: Crypt
• Care Level: Easy
• Growth Rate: Slow to moderate
• Lighting: Any
• Nutrients: Substrate

Plant Care

Promote healthy growth by following these steps: 

• Provide ample nutrients: Aquatic plants need a range of key nutrients to thrive. Provide this by adding quality fertilizer to the tank water or substrate.
• Prune them often: Like other plants, aquatic plants need pruning. Invest in a good pair of pruning scissors, and watch your plants for signs of overgrowth.
• Keep the tank clean: Your plants will only thrive in clean waters. Install a low-flow filter to help remove toxins. 
• Maintain the aquatic environment: Ensure toxin levels remain low. Also, watch for things like brown algae growth, which is harmful to aquatic plants.

Common Mistakes

 The three most common mistakes new aquarists make are as follows:

1. Over- or under-lighting the plants
2. Planting or anchoring the plants incorrectly
3. Failing to perform frequent water changes

Follow the advice outlined in this guide to give your aquatic plants the best possible life. 

Plant Revival

 Here are some different ways to help revive your browning or yellowing plants: 

• Fertilization: If your plants lack essential nutrients, they may turn brown over time. Adding fertilizer to the water or substrate may help revive it in this case. 
• Trimming damaged leaves: Sometimes, your plants may just need some trimming. Use pruning scissors to trim away any damaged or discolored leaves. This will allow healthier leaves to grow in their place.
• Changing water chemistry: Poor water chemistry can cause browning issues. Consider changing the water chemistry to see if this revives your plants. Do this by adding water conditioner or tannin-rich plants, for example. Also, ensure there are adequate CO2 levels at all times.
• Replanting: Overcrowded plants have a hard time growing well. Consider replanting some of your plants so there’s more space between them. This way, they’re not fighting each other for nutrients. 

In some situations, your aquatic plants will not be salvageable. For example, plants taken by disease are unlikely to get better.

Keep Those Aquarium Plants Looking Great!

There are various reasons why aquarium plants might become brown or yellow. Common examples include improper lighting, poor nutrition, and incorrect planting techniques. 

Fortunately, saving your plants is usually possible. Ensure they meet their basic needs and take proper care of the aquarium environment. 

Aquascaping is a complex but rewarding hobby.

If you found this helpful, share it out with other aquarium enthusiasts!