How to Care for Red Aquarium Plants?

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Plants play vital roles in an aquarium’s ecosystem beyond the mere esthetical benefits. They combat ammonia and nitrites, improve the water’s oxygenation, and provide fish with hiding, food, and a more natural-looking environment. But, since all plants deliver these benefits, we typically rely on their looks when choosing our favorites. This is where red plants come in.

Red plants play a special place in every fish hobbyist’s heart for good reason. Thanks to their plus of color and color variations, they work great in most tank settings. Many plant species display varying colors like magenta, pink, purple, bright red, orange, and many varying cues of these colors. Using them in addition to green species will boost their presence even more.

But what many people don’t know is that red plants require special care compared to their green versions. Let’s dissect those special requirements in detail.

Do Red Aquarium Plants Need CO2?

Some do, some don’t. To understand this whole notion, we must first explain what CO2 injections are and what purpose they serve. CO2 injections refer simply to the act of infusing tank water with additional CO2. This is only necessary in planted aquariums due to the fact that, during the day, tank plants consume CO2 and produce O2.

This makes plants a vital addition to any aquatic environment as they represent the building block of underwater life. Your fish will consume the O2 produced by plants and produce CO2, and the entire cycle repeats indefinitely. But, sometimes, this isn’t enough, especially if you have too many plants and not enough fish.

CO2 injections will provide plants with additional CO2 to support their life cycle. But it’s important to know that they’re not always necessary. Some variations of red plants require CO2 to achieve their distinct coloring, but others don’t. For instance, Nymphaea Zenkeri and Ludwigia Repens can grow just fine without the need of any additional CO2.

Rotala Macrandra and Helanthium Tenellum, on the other hand, require CO2 injections both to grow and optimize their coloring.

What is the Best Light for Red Aquarium Plants?

All plants require adequate lighting to grow since plants use photosynthesis to ‘breathe.’ This process defines the plant’s ability to transform CO2 into O2 and vice-versa, depending on how much light they’re getting. This is why plants and trees consume CO2 and produce O2 during the day and reverse the process during nighttime when light levels are extremely low.

But what type of lighting do red plants require? Many aquarists use various LED lights displaying different colors, and each will come with unique effects, benefits, and even downsides. Here’s what I mean by that:

  • Red light – 620nm to 700nm – Red light stimulates photosynthesis and promotes growth. Plants will develop longer leaves and will grow taller as a result. This is especially a great option for upright tank plants.
  • Yellow/Orange light – 575nm to 620nm – Yellow light will actually inhibit the photosynthesis process, causing the plants to remain smaller and develop slower over time. Orange light, on the other hand, has beneficial effects, especially when leaning more towards red.
  • Greenlight – 500nm to 575nm – Boosts the effectiveness of the photosynthesis process. Greenlight actually comes with unique benefits compared to red light since it reaches lower canopy ‘feeding’ leaves that don’t have access to red light. This will stimulate photosynthesis across the entire plant, rather than higher-to-medium leaves-only.

Other light forms include infrared, far-red, blue-violet, and other forms with varying effects like boosting leaf expansion or benefitting the plant’s flowers and fruits. In essence, plants need red light more than anything since it better mimics natural lighting coming from the Sun.

If you can provide your plants with natural lighting, do so. If not, provide plants with a mix of red, blue, and orange light, as they all complement each other. Red is most effective at boosting the effectiveness of photosynthesis and stimulates vertical growth. Blue and orange allow plants to grow more well-rounded and boost their coloring and leaf shape, and size.

What Makes Aquatic Plants Red?

Most people don’t know that many green tank plants can also become red under certain conditions. There are plant species that are natively red, like Ludwigia Repens, Alternanthera Reineckii, or Ludwigia Palustris. Others, however, are green, rusty, or a mix of both under normal conditions. You need special conditions to trigger their red appearance.

And it all comes down to 3 basic strategies:

  1. Brighter lighting – All plants display better pigmentation in stronger lighting, so upping the environmental light will boost your plant’s coloring. One of the downsides is that algae also require bright lighting to grow, so you might want to keep an eye on those. Also, some tank plants prefer living in poorer lighting conditions, which goes to show that this approach isn’t universally beneficial.
  2. Use the red-and-blue spectrum – Red and blue lights will boost your plant’s pigmentation, while red lighting will also enhance the color naturally. Just don’t overuse red LEDs since too much red can monotonize the entire tank.
  3. Limit the nitrates – Plants that lack nitrates showcase difficulties in producing chlorophyll (their green pigment), causing them to grow redder than they usually would. This is also not a universal approach since plant species like Rotala Macrandra or Ludwigia Pantanal seem unaffected by the dip in environmental nitrates. Also, some species require a surplus of nitrates to grow properly, and depriving them of this essential nutrient may inhibit their growth.

Why Are My Red Aquarium Plants Turning Green?

Many aquarists will see difficulties turning and maintaining their plants red, and there’s always a cause for that. Sometimes there are multiple causes, such as:

  • Reducing the lighting levels or changing the spectrum
  • Keeping the nitrate levels over 10 ppm, nourishing the plant’s chlorophyll reserves and make them greener in the process
  • Not having enough iron in the water
  • Not enough CO2 in the water, at which point supplementation via CO2 injections is necessary

If these conditions are not met, your plants will either display very light red nuances, refuse to turn red at all, or even turn green over time.

Why Are My Red Aquatic Plants Dying?

There are multiple reasons for your tank plants dying, most of which apply to plants in general, not just the red ones. These include:

  • Lack of proper lighting – All plants require light to fuel their photosynthesis process. Without it, they will wither and die fast. Even plants living in low lighting still need some lighting to survive. If your plants show signs of dying off, see whether the lighting is the issue. And keep in mind that some plants require more lighting than others.
  • Excess fish wasteRotten food and stagnating fish waste in unclean tanks can lead to plant death. These residues will produce sulfur and ammonia in amounts higher than most plants can handle, leading to root decay and killing the plant in the process. You can prevent this problem by cleaning the tank regularly and performing water changes whenever necessary.
  • Too powerful filtration system – The filtering system is typically a good addition to a fish tank, but not always. Too potent tank filters can have the opposite effect, diluting water nutrients, filter out too much CO2, and even creating powerful currents, unearthing the plants’ roots. All these issues can lead to plant death over time and affect your fish’s quality of life along the way.
  • Lack of nutrient supplementation – Some plants need fertilization to grow and remain healthy over time. Iron, potassium, and phosphate are 3 of the most essential nutrients providing your plants with a healthy growth cycle. Lacking nutrition may lead to insufficient plant growth, inadequate coloring, or even plant death.
  • Improper substrate – Rooted plants need a stable and strong substrate to bury their roots and anchor themselves to withstand water currents and fish activity. Using gravel or other large-particle substrates won’t allow plants to root themselves and extract nutrients properly.
  • Improper tank mates – You can’t pair your red plants with plant-eating aquatic creatures and still wonder what the problem is. Many species of fish and snails will consume plants or plant roots with devastating effects for the latter.

If you notice your red plants turning green, struggling to keep their coloring, or starting to die off, assess the situation and look for the cause. Sometimes it’s obvious, and so is the solution.

Best Red Aquatic Plants for Beginners

You’ve set up your tank, got the fish, mounted the equipment and decorations, and now you’re ready to get a handful of red plants. But which should you get? Here are 3 of the most beginner-friendly red tank plants I recommend getting:

  1. Alternanthera Reineckii – This plant is green at its origin but will become red under specific environmental conditions. Providing moderate lighting 10 hours per day is usually enough to trigger the plant’s red ‘personality.’ This species will adapt and thrive to pretty much all environmental conditions, and it’s really easy to care for. Provide water temperatures between 74 to 80 F, ensure adequate fertilization if necessary, and keep the water clean and your Reineckii will thrive.
  2. Ludwigia Repens – This is a fast grower that usually displays red stems and green leaves. Certain species will also display red leaves, especially under higher lighting conditions. This species is very beginner-friendly since it doesn’t require CO2 supplementation or any other special maintenance gigs. However, it does require additional lighting to remain healthy and preserve its coloring.
  3. Ludwigia Palustris – Ludwigia Palustris often has the ‘Super Red’ syntax attached to its name due to its intense coloring. It is easy to maintain, grows fast, and retains its red coloring even in medium lighting.

There are many other tank plants to consider in the red spectrum, each requiring various environmental conditions and maintenance approaches. I’ve already written a more comprehensive list of red aquarium plants you might want to check for additional information.


Red plants are slightly more demanding in terms of care compared to their green counterparts. The good news is that beginners also have a wide selection of easy-to-maintain plants to choose from.

Provide your plants with adequate lighting, ensure proper supplementation, and consider CO2 injections to boost your plants’ red nuances.

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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