Aquarium Plant Leaves Turning Transparent – 7 Reasons

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Live plants are undoubtedly a wise addition to any aquarium. They oxygenate the environment, keep the water cleaner, balance water chemistry, and provide fish with safety and hiding. The problem is that many inexperienced aquarists take the plants for granted.

They will plant them and only remember about them when plants begin to display health issues. Today, we will discuss a common issue with live aquatic plants that most people will face eventually. We’re talking about the plants’ leaves turning transparent for no apparent reason.

This is a sign of disturbances in water quality or that the plant is experiencing some type of deficiency.

7 Reasons Aquarium Plant Leaves Turning Transparent

Knowing what causes your plants’ leaves to turn transparent is essential to reversing the process fast. Whatever’s affecting your plant will soon cause irreversible damage if you ignore the problem for too long. So, here are 7 of the most widespread problems that will cause plant leaves to turn transparent:

– New Environment

This is a common issue and one that requires a careful approach. Most aquatic plants are sensitive to new environments since these will almost never be identical to those the plant comes from. The water chemistry will be different, and so will the nutrient content, temperature, lighting, substrate, and a number of other factors.

For starters, your plants require anchoring support because their roots are either underdeveloped or need time to anchor themselves. Relying on a soil substrate will make your life a lot easier in this sense because soil offers better anchoring assistance. Sand or gravel, however, aren’t as effective in this sense due to not being as dense.

Sand can also become extremely compact, strangling the plant’s roots and complicating the nutrient extraction process. But this is a more complex topic for another time.

Either way, you should be mindful about the plant’s environmental requirements and give it time to adapt to the new setting. So long as all parameters fall between the ideal values, your plant will undoubtedly bounce back soon.

– Insufficient Lighting

This is a rather common problem for indoor aquariums. Many aquariums lack the necessary access to sunlight, which will affect the plants’ ability to perform photosynthesis. If not enough light is available, the plant will no longer be able to perform effective photosynthesis. The photosynthesis process is basically similar to animal digestion since plants synthesize the necessary nutrients from their surrounding environment.

Plants will consume oxygen and produce CO2 if sufficient light is unavailable. This will cause 2 major problems: plants will begin to die off due to nutrient deficiencies, and the fish will begin to suffocate. The latter is the direct result of the plants consuming oxygen and producing excess CO2 in the process, which happens when lights go out.

When it comes to the necessary amount of light, we have 2 core components:

  • Light duration – Plants require a steady day/night cycle to regulate their internal processes. The ideal timespan would be 8-10 hours of light during a 24-hour period. This is enough for plants to perform optimal photosynthesis and remain stable and healthy in the long run.
  • Light intensity – This is a more delicate point because not all plants require similar light intensity. Some plants do just fine in low-light conditions, while others prefer brighter environments. The balance is the key here because the higher the light intensity, the higher the chances of algae bloom. Algae thrive in aquatic environments with a lot of light, so be careful about that.

The light’s spectrum also plays quite a role in proper plant development. Red and blue are considered among the most ‘nutritious’ light colors, while plain white falls in the meh region. It’s good, but it doesn’t provide the plant with as many benefits.

– Nutrient Deficiency

Aquatic plants get their nutrients differently based on their species. Rooted plants extract nutrients directly from the substrate via their root system. Floating plants don’t have roots, so they feed via their leaves and stem, extracting nutrients from the water around them. Plants feed on chemicals resulting from dead matter, fish waste, food residues, and another type of organic waste, if available.

Needless to say, plants don’t need any assistance in the wild since they live in an open environment. So, there’s constant nutrient cycling there for them to harness. An aquarium, however, is a closed environment. So, relying on available organic matter may not cut it since it’s often not enough.

This means that plants also require additional fertilization based on their needs, the available substrate, the tank’s size, etc. Here are some key talking points to note:

  • Enriched soil is the optimal substrate – Plants rarely need additional fertilization when kept in enriched soils. Soil is the best option for plants due to the high nutrient content and will keep the plants well-fed for years. Sure, soil doesn’t pack the same esthetic punch as sand or gravel, but its nutritional value is undeniable.
  • Sand and gravel are inert substrates – By ‘inert,’ we mean devoid of any nutritional content. So, rooted plants cannot survive in sand or gravel without additional fertilization. This comes in the form of root tabs planted in the substrate, near the plant’s root system. You will need to use multiple tabs, depending on how many plants you have, and change them regularly, depending on how fast your plants deplete them. Some plants need new tabs once a month, while others require 3-4 tab changes per week.
  • The duality of liquid fertilizationLiquid fertilization is necessary for floating plants since these get their nutrients from the water column. The type and amount of plant fertilizer to use depends on the plant’s size, the number of plants you have, and the size of the tank. Keep in mind, liquid fertilizers have been linked to algae overgrowth since algae also consume liquid fertilizers. So, make sure you don’t overfeed your plants. After all, they don’t need as much additional fertilization if they live in a fish tank with plenty of waste.

Finally, plants can display a variety of nutrient deficiencies, depending on which element they’re lacking. For instance, the leaves will turn yellow when lacking nitrogen, turn pale with dark veins when lacking iron, or exhibit yellow or brown holes when lacking potassium. Learning how to read your plant’s needs will cut your headaches at least in half.

– Water pH

Most aquatic plants thrive in a pH range of 6.0 to 7.0. Some will even reach 8.0. The problem is that improper pH levels will considerably affect the plant’s growth and health. This forms the basis of a confusing topic because plants influence the water’s pH, while the water’s pH also influences plant health and growth.

So, there’s a balance here that needs maintained. As a general rule, try to keep the tank’s pH between 6.0 and 7.5 if possible. This range may vary, as some plants can go as low as 5.0 and as high as 8.0. Java fern, java moss, and hornwort come to mind in this sense. The latter can even get to 9.0 in some cases.

– Ammonia Level

This is another tricky point because plants actually like ammonia. They even need it, as it’s part of their diet. Ammonia is the natural result of dead and decaying matter, including plant one. Nothing will consume ammonia in the tank other than the plants, which goes to show that live plants are sometimes necessary. Especially in a tank with extreme poopers like goldfish or cichlids.

However, sometimes even plants have difficulties dealing with the ammonia content in the tank. The problem is that getting ammonia in the water is the easiest thing in the world. Everything produces ammonia, including fish poop, dead fish, food residues, and even dead plant matter, like rotting leaves. Ammonia is even produced by bacteria in anaerobic pockets in sand substrates.

Eliminating the chemical from the water, though, that’s an entirely different story. Plants will do some of the work by using ammonia as food, but even they are limited in this sense. If the amount of ammonia present in the tank exceeds the plant’s ability to remove it, you’ll have a problem on your hands. The excess ammonia won’t only kill the fish but kill the plants too.

So, you should always monitor ammonia levels in the tank and:

  • Clean fish waste and food residues regularly to keep the environment stable
  • Clean fallen leaves to prevent them from decaying in the tank
  • Perform regular partial water changes (at least once a week) to dilute ammonia, nitrites, and nitrates, and oxygenate the environment
  • Prevent overfeeding to minimize the accumulation of food residues on the substrate
  • Vacuum or clean the substrate as often as necessary to prevent waste from burying itself inside and rotting out of sight

– Lack of CO2

CO2 is the core component of plant ‘respiration.’ Plants use CO2 from their environment as fuel for their internal processes, along with light and other nutrients, to produce oxygen and support their physiological functioning. Wild plants have no problems getting access to more CO2 than they need.

Aquarium plants don’t have that luxury because aquariums are closed systems with only limited CO2. The filtered water you’re using for your aquarium (hopefully) is pretty much depleted of CO2. Aquatic plants also decay less than their land counterparts, so there isn’t much residue to produce CO2. Combine these factors with a steady cleaning and maintenance routine (which is necessary) that will lower the CO2 content even further, and you have a problem on your hands.

Plants will begin to show signs of distress and even die when lacking CO2. In this case, CO2 injections may be necessary to correct the problem. Just keep the following:

Excess CO2 will kill your fish. The acceptable CO2 value for fish is below 30 ppm. Anything above that will quickly become toxic for your fish, affecting their ability to breathe and leading to suffocation fast. You can tell that your fish are experiencing respiratory issues if they appear lethargic, exhibit accelerated gill movement, and tend to swim near the water’s surface more often.

You should also be mindful about the chemical changes in the water during nighttime. Plants consume CO2 and produce O2 during the day, but their physiological functioning changes during nighttime. Plants will, instead, consume oxygen to produce CO2 when the light intensity drops low enough.

In other words, even a value of 30 ppm may not be as safe as you think. That value will go up during night time, especially in heavily planted tanks.

So, plants require CO2 to thrive, but fish not so much. Make sure you find a balance between the two, or death will ensue.

– High Nitrate Level

Plants use nitrates as a food source, but more isn’t always better. If nitrate levels are too high, your plants may begin to exhibit health problems. The same happens if nitrate levels drop too low, causing the plant to experience nutrient deficiency.

The ideal value, in this sense, sits at around 50 ppm. Naturally, nitrate levels will always fluctuate, even in a well-established and well-maintained tank. So, you should always monitor nitrate levels to make sure it’s safe for both plants and fish.

What to do With Damaged Leaves?

If your plant exhibits damaged leaves, you should first assess the severity of the damages. If the situation isn’t too serious, the plant may recover in full once you correct the trigger. But, if not, you might want to remove the dying leaves manually. They will fall off anyway.


Most aquarium plants are hardy and will adapt to a wide range of environmental conditions. However, as you’ve been able to see, the situation is often more complex than that. Your plants may sometimes exhibit health problems that require fast fixing to prevent them from aggravating.

Fortunately, I’ve provided you with 7 of the most common issues and their respective solutions. So, you have a great starting point in this sense.

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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