CO2 – how to provide plants in an aquarium with proper nutrition

If you’re enthusiastic about maintaining a healthy aquarium, you are aware of the vital role plants play in fostering a positive environment. Have you ever wondered, though, what causes them to become so vibrant and lush? Carbon dioxide, or CO2, is one important component. The development and general health of the plants in your aquarium can be greatly enhanced by adding the proper amount of CO2.

CO2 is necessary for photosynthesis in aquariums, which is how plants turn light into energy. Insufficient CO2 can cause plants to struggle, which can result in stunted growth or even algae issues. Getting the proper amount of CO2 into your plants will improve their nutrient uptake and help them outcompete undesirable algae for available resources.

You can supply CO2 to your aquarium in a number of ways, ranging from easy do-it-yourself options to complex systems. The health and aesthetics of your tank can be greatly improved by knowing how to manage CO2 efficiently, whether you’re just getting started or want to improve your setup. We’ll go over several approaches and pointers in this guide to help your aquarium plants get the nourishment they require to flourish.

Making sure aquarium plants get the proper amount of carbon dioxide (CO2) is essential to their survival. CO2 is an essential nutrient for plants because it facilitates photosynthesis, which makes them robust and healthy. This post will discuss easy and efficient ways to supply your aquatic plants with the CO2 they require, either by adding extra systems or using natural processes. You can cultivate a vibrant and well-balanced underwater environment where your plants can thrive by monitoring and controlling CO2 levels.

Carbon dioxide is the most important condition for the development of aquatic plants

The majority of organic substances are primarily composed of carbon compounds, which is the basis of life on Earth. Most plants produce "building material" on their own if animals eat everything they require to create body tissues.

The process by which plants obtain glucose, the most basic carbohydrate, is known as photosynthesis. The primary response:

Energy is absorbed during synthesis, and each glucose molecule is formed using roughly 674 cal. Chlorophyll and other pigments, or chromophylls, are absorbed by molecules and provide it to plants.

Additionally, the most basic carbohydrates are transformed into; by the action of enzymes

  • more complex sugars;
  • amino acids, proteins, fats, for the synthesis of which macro- (nitrogen, phosphorus, potassium) and microelements are required.

This guarantees the growth of plants, development of root systems, accumulation of leaf mass, etc.

Certain plants can obtain their carbon from other substances. For instance, a number of aquatic plants, including echinodorus, vallisneria, hornwort, anubias, and elodea, have adapted to consuming carbonates (CO3-) and hydrocarbonate ions (HCO3-), the presence of which is caused by the concentration of hardness salts being non-zero.

Therefore, a number of elements are required for the plant’s development:

  • The presence of water (not relevant for aquatic plants, since water is their native habitat).
  • A source of carbon, for most – CO2.
  • Energy (read: lighting).
  • Macro- and microelements.

Light energy and nutrients are practically never a problem for aquarium plants. Natural light and materials found in the soil are sufficient for the majority of them. It is simple to set up artificial lighting and fertilization for the pickier ones. There are some issues with the primary component of the structure (carbon).

The reason for the lack of carbon (carbon dioxide)

There is a straightforward explanation for the lack of carbon compounds in artificial home reservoirs.

Under normal circumstances, reservoir carbon sources include:

  • Carbon dioxide from the atmosphere. CO2 dissolves in water much better than oxygen, but is also easily released. At the same time, due to the large area of ​​contact between the water surface and the air, the concentration of CO2, obtained from this source can be quite high.
  • Salts (carbonates) of various elements. Along with poorly soluble ones, sources also bring easily soluble ones (for example, sodium salts) into water bodies.
  • Carbon dioxide released during breathing by representatives of aquatic fauna. This source also provides an intensive supply of CO2.

Consequently, the range of carbon dioxide concentrations in natural reservoirs is 3 to 10 mg/l in flowing conditions and up to 30 mg/l in stagnant conditions. This is more than enough to support aquatic plant growth.

Home aquariums, especially those with sizable volumes, present a different scenario:

  • Aquarists, as a rule, strive to reduce the carbonate hardness indicator to the recommended values.
  • The surface area is not enough to enrich the volume of water with carbon dioxide.
  • Those who specialize in plant breeding are very reluctant to populate their aquariums with fish (especially large ones) and invertebrates.

Therefore, the underwater flora will be condemned to its deficiency and development issues in the absence of an additional carbon source. Systems for adding CO2 to the aquarium can solve the problem.

Optimum concentration of carbon dioxide in aquarium water

Ensuring a carbon dioxide concentration that corresponds to the natural habitat of aquarium plants is the most effective way to promote their growth and harmonious development.

Diverse aquaculture sources and forums offer varying CO2 concentration thresholds. As a result, knowledgeable aquarium enthusiasts frequently discuss concentrations between 7 and 30 mg/l, while producers of aquarium supplies, such as CO2 supply systems, prefer to work with numbers between 15 and 40 mg/l.Dennerle, for instance, suggests keeping a concentration between 15 and 30 mg/l, with an ideal range of 20 to 25 mg/l.

The lower allowable limit of concentration is generally estimated. If it isn’t higher than 3 mg/l, aquatic plants will truly become hungry.

The upper limit is a little trickier to estimate. Generally, consideration is given to the fact that there is a strict correlation between the CO2 content of water and its carbonate hardness (kH) and acidity index (pH). It makes it possible to determine the carbon dioxide concentration using pH and kH. However, the opposite is also true: a rise in carbon dioxide content causes a fall in pH and an increase in hardness.

Therefore, it is possible to alter the water’s parameters in an aquarium and put aquatic life in danger by adding artificial gas to the tank. High hardness and low pH won’t improve the health of the aquarium flora, but a CO2 concentration of 30 mg/l can become hazardous for fish and invertebrates with an initial value of kH of about 4 degrees and a neutral reaction.

The term "carbonate buffer" refers to a concept. The main idea behind the phenomenon is that high carbon dioxide concentrations are needed to raise pH significantly at high kH levels. As a result, an aquarium’s occupants can tolerate a higher CO2 content in harder water without suffering permanent harm.

The importance of balance

It is obvious that stable growth and development of aquarium plants cannot be ensured by simply caring about the ideal concentration of carbon dioxide in the water. It’s also important to keep in mind the other elements—nutrient availability and lighting—that were previously discussed.

Therefore, experts believe that the following parameters (given for a water column of 0.4-0.5m) are sufficient for stable, but not rapid, growth of aquarium flora:

  • Carbon dioxide concentration 5-7 mg/l;
  • Illumination – 0.4-0.6 W/l.

In this instance, the nutrients produced by nitrifying aquatic organisms and microorganisms are adequate.

An increase in illumination to 0.7–0.8 W/l will be necessary when the CO2 content rises to 15-20 mg/l. You will need to supplement with nutrients, mainly nitrogen. Aquarium tests should be used to determine whether phosphorus and potassium supplements are necessary.

Aquarium owners should keep in mind that higher aquatic plants exhibit their full potential and prevail in competitive situations when they are in a state of balance. Because of their quick growth, the algae are prevented from growing and go "on a starvation diet," keeping the aquarium tidy and thriving.

However, simple ancient algae (filamentous algae, also known as "Black beard"), which are better suited to harsh environments, take control as soon as the equilibrium is upset. Their expansion causes the situation to worsen even more.

CO concentration control2 in an aquarium

The most precise and efficient way to track CO2 content2 is to measure pH and carbonate hardness. As mentioned earlier, there is a strict dependence between these indicators and the amount of carbon dioxide in water. A table provides an overview of the values at various pH and kH. The ideal concentration of 15–30 mg/l is indicated in green within it.

The primary benefits of this approach are:

  • Accuracy of determining the concentration of carbon dioxide;
  • Efficiency of control.

Many, even highly skilled aquarists, favor more straightforward techniques:

  • Using drop checkers

A small vessel with a specific composition—typically water with a kH of 4 and a chemical indicator of acidity, pH—is used as such an indicator. The container is submerged in the aquarium; as the solution comes into contact with the water, the CO2 content causes the color to change.

The method’s simplicity is its advantage; its drawbacks are its limited operating time (although the indicator liquid can be replenished) and its inertia (it takes from 0 to change the drop checker’s color).between two and five hours). The same idea underlies the operation of many test indicators, which are widely available in pet stores.

  • Counting gas bubbles coming from the system

An aquarium is a transparent container with water in it that makes it easy to watch the gas release. A bubble counter is integrated into the line that runs from the system to the aquarium. Using the quickest method, you can estimate the CO2 concentration during supply before it dissolves in water.

According to theory, 1 bubble per minute per 10 liters of aquarium volume equals 7–19 mg/l of CO2. Although control accuracy is obviously not very high, it is still feasible to estimate concentration and avoid going overboard.

  • Intensity of pirling ("bubbling").

The amount of carbon dioxide in the atmosphere has a direct impact on how much oxygen is released by plants. Many seasoned aquarium keepers can visually determine the indicator with a high degree of accuracy by looking at the "bubbling" of plants and the water’s chemical makeup.

Topic CO2 – How to Provide Plants in an Aquarium with Proper Nutrition
Why CO2 Matters CO2 is crucial for photosynthesis, helping plants grow and stay healthy. Without enough CO2, plants can"t produce the energy they need.
CO2 Sources There are two main ways to add CO2: using pressurized CO2 systems or DIY methods like yeast-based setups. Pressurized systems are more efficient but costlier.
CO2 Levels Ideal CO2 levels are around 20-30 mg/L. Too little CO2 can stunt plant growth, while too much can harm fish. Regularly test and adjust levels to find the right balance.
Adding CO2 Install a CO2 diffuser or reactor in your tank. Place it near the filter outlet to ensure even distribution. Monitor how well the CO2 dissolves and adjust as needed.
Other Tips Ensure good water circulation and avoid overfeeding fish, as excess nutrients can lead to algae growth. Regular water changes help maintain a healthy balance.

The proper CO2 levels for aquarium plants are necessary for a flourishing underwater garden. One essential nutrient that makes plants grow lush and vibrant is carbon dioxide. Without it, your tank may exhibit stunted growth or an overgrowth of algae. Maintaining a consistent CO2 supply can be crucial to creating a well-balanced, exquisite aquarium.

Using a CO2 injection system is among the most straightforward ways to increase CO2 levels. Depending on your requirements and the capacity of your tank, these systems can be basic or sophisticated. A pressurized CO2 setup may be the simplest to operate and provide reliable results if you’re just getting started. A DIY yeast-based CO2 system can be a more affordable option for people with smaller tanks.

The secret to maintaining the health of your plants is routinely checking and adjusting the CO2 levels. Purchase a CO2 test kit to make sure you’re giving the appropriate amount. Fish can be harmed by too much CO2, and plant growth can be stunted by too little. Your plants and aquatic life will thrive in a harmonious environment if you can find the right balance.

Recall that CO2 is only one component of the problem. You can make sure your aquarium plants receive the complete care they require by combining it with appropriate lighting and nutrient dosing. You and your aquatic companions can enjoy creating a flourishing underwater paradise with a little effort and the appropriate equipment.

Video on the topic

Carbon dioxide CO2 in the aquarium Standards, influence, control

4 pcs of the greenest aquarium without CO2 and fertilizers! As if I returned to the times of the USSR!

IS IT POSSIBLE TO GROW PLANTS WITHOUT CARBON DIOXIDE?

Aquarium plants without CO2 | Maintenance of plants without CO2 | Aquarium without CO2 (#64)

A very simple and beautiful aquarium without chemicals and CO2. Using my 30-liter cube as an example.

A very simple CO2 system for an aquarium. Competition!

Plants in an aquarium, how to grow them and whether they need CO2 or not ??

What part of aquarium maintenance do you consider the most difficult?
Share to friends
Elena Grishina

Ecologist and aquarist with a special interest in creating balanced ecosystems in aquariums. Main focus — ecosystems that require minimal human intervention. I support a natural approach to aquarium care, where each element plays its role, helping to maintain harmony in a closed ecosystem. I promote sustainable aquarium keeping and respect for nature.

Rate author
InfoProekt24.com
Add a comment