How to stabilize CO2 in an aquarium?

One of the benefits of injecting pressurized CO2 into a planted tank is the control it gives us over how much CO2 enters the aquarium water. While we can control this process stage, we must consider what is required to stabilize the gas within the water column and ensure our aquatic plants receive a consistent supply of vital CO2 to thrive.

planted tanks with lily pipes

What does "stabilize CO2" mean?

The term 'stabilize co2' refers to ensuring a consistent carbon dioxide (CO2) level within an aquarium, for example, when using pressurized CO2 systems. This balance is important for healthy aquatic plants, which rely on a certain amount of CO2 to photosynthesize and grow. Stabilizing the CO2 level in an aquarium helps to maintain a healthy and thriving aquatic environment.

Why are CO2 levels important in an aquarium?

Plant growth requires Carbon Dioxide to photosynthesize, and without additional co2 supplements, plans will not thrive. If we want a thriving, vibrant aquascape, we must understand the importance of installing and correctly managing healthy CO2 levels using a quality CO2 system. When CO2 levels are too low, plants cannot photosynthesize efficiently, resulting in poor plant growth. On the other hand, if CO2 levels are too high, aquatic life can suffer from oxygen deficiency and stress. Therefore, keeping CO2 levels within an optimal range for underwater plants and aquatic life is vital.

Not all plants are created equal

Something that often causes issues for new or inexperienced planted tank enthusiasts understands that an aquarium plant requires specific care and that not everything in a planted aquarium is ok with the same gas levels, pH levels and nutrient levels. For this reason, plant selection should be researched, and failure to do so may result in unsatisfactory growth or even the death of all the aquarium plants.
You can find information on the carbon dioxide levels for each plant from the plant producer's website.

forest style planted aquarium

What are the signs of too much CO2?

We can identify too much CO2 in an aquarium by observing a few signs: the aquarium water becomes highly acidic, causing fish and other aquatic life to become stressed. In these situations, fish often breathe directly from the water's surface. In addition, plants will begin to show signs of yellowing or wilting as they cannot absorb enough CO2 for photosynthesis. If left unchecked, these symptoms can quickly lead to a collapse of your aquascape.

Using a drop checker offers an easy way to keep track of the CO2 levels in your aquarium. This device measures the amount of CO2 in the water. A drop checker should maintain a lime green colour when CO2 levels are good. If there are increased CO2 Level will turn a much darker green. Drop checkers can alert us when they are too high or too low, allowing us to make timely adjustments.

co2art drop checker

We can also use test kits to measure pH levels in our aquariums, which will better indicate how much CO2 is in the water. Furthermore, regular water changes can help reduce levels of CO2 and other dissolved substances in our tanks.

How to balance CO2 levels in the aquarium water.

Once you have correctly installed your CO2 system, maintaining the most efficient co2 levels for your aquarium is essential. To ensure that your tank remains healthy, you may need to adjust the levels of CO2 in your aquarium using the needle valve on your bubble counter. You can monitor CO2 levels using a drop checker to measure the presence of CO2 in the water. By monitoring this daily, you can ensure it stays within ideal parameters for aquatic life. You should also check your aquarium's temperature, as heat can cause fluctuations in CO2 levels. Additionally, it is recommended to regularly check the pH levels in your aquarium using liquid pH test kits or a pH probe as this can also help you determine if you need to adjust the CO2 levels. Regularly testing and adjusting your aquarium's CO2 levels can create a healthy environment for your fish and plants. This will ensure they grow and thrive in their new home.

Know how to fix too much CO2 in your aquarium.

If you discover your drop checkers turned dark green and your CO2 levels are too high, don't panic. You can resolve this issue simply by performing some essential maintenance. The first thing to do is a large water change. This will immediately reduce the amount of CO2 in the aquarium, eliminating the possibility of breaching the toxicity threshold. Increase aeration in your aquarium by adding an air stone, and regularly check the water levels to ensure sufficient oxygen for the fish. You may need to reduce the food you feed your fish, as this can contribute to higher CO2 levels. With these simple steps, you can keep your aquarium healthy and thriving with the right level of CO2.

What does the term 'gaseous exchange' mean?

You may have heard this term used in aquascaping communities and wondered what it means. It may have even put you off setting up a CO2 system for yourself. Still, when hobbyists mention gas exchange, they refer to the process of exchanging carbon dioxide and oxygen on the water surface between the aquarium water and the atmosphere. This is a crucial part of keeping your fish healthy, as it ensures they have access to adequate levels of CO2 and oxygen. A lack of gaseous exchange will result in insufficient oxygen for your fish, decreasing their overall health. The same goes for too much CO2 being introduced, resulting in a dangerous decrease in oxygen levels and a potentially damaging low pH. As such, it is essential to understand the concept of gaseous exchange and how it affects your aquarium.

When setting up a CO2 injecting system and using an in-tank diffuser (check out our range of in-tank diffusers right here), placing the diffuser close to the filter outlet is good practice. By doing this, the tiny bubbles containing CO2 will be spread across the aquarium water. This process allows for more significant dissolved CO2 and is more widespread in aquarium water. It will also create a higher chance of efficient gaseous exchange, as the CO2 bubbles are more likely to come into contact with oxygen and be exchanged.

What happens if there is not enough CO2 in the aquarium?

If your drop checkers turned dark blue, you could assume your aquarium co2 levels have dropped low enough to be inefficient. This can be fixed by manually increasing the amount of CO2 injected into the aquarium or adjusting how long your injector will run throughout the day. Sometimes it is the case that the output pressure on the CO2 regulator is set too low. It’s essential to ensure you add enough CO2 to maintain a healthy level in your aquarium, which is essential for plants to grow and remain healthy. If there is not enough CO2, the aquarium will become deficient in oxygen which could result in plant death or algae growth. It can also cause a decrease in pH levels, damaging fish. Therefore, you must regularly monitor your aquarium's CO2 levels and adjust accordingly if necessary. Doing so will ensure your aquarium remains healthy and vibrant.

I have a deep tank. Does that change anything?

Additional caution should be taken if you inject carbon dioxide into a deep aquarium. The gas will accumulate near the surface and not reach the bottom of your tank. This can cause areas of inadequate CO2 levels at deeper parts of your tank, resulting in stressed plants and increased algae growth. To ensure that all areas of your tank are getting enough CO2, you'll need to adjust the flow rate of your CO2 diffuser accordingly. Additionally, be sure to check deeper areas for signs of stress or algae growth to verify that all parts of the tank are receiving enough carbon dioxide. Proper monitoring and adjustments can keep a deep aquarium healthy and thriving. A deep aquarium requires the same water parameters and care as a shallow aquarium but with the added challenge of adequately diffusing carbon dioxide. You can keep your deep tank healthy and beautiful with careful monitoring and adjustments.

My CO2 system is running as it should but I still have algae issues. What should I do?

If your aquarium is experiencing algae issues, it's important to check your CO2 levels. Algae can be caused by too little or too much carbon dioxide in the tank. If you're unsure if you have the right amount of CO2, you can test the levels with a drop checker or an aquarium controller. You can also monitor oxygen levels and nutrient availability to ensure everything is balanced in your tank. If all parameters are within the normal range and you still have issues, it may be time to look at other variables, such as lighting, water circulation and filtration. You can keep your aquarium healthy and beautiful with careful monitoring and adjustments.