What happen if too much of CO2 in planted tank?

Planted aquariums are a popular addition to many homes and offices. They not only look beautiful, but they also provide numerous benefits, such as improving air quality and reducing stress levels. One important aspect of maintaining a healthy planted aquarium is providing the right amount of carbon dioxide (CO2) to the plants. However, too much CO2 can have detrimental effects on the fish and plants in the tank. In this article, we will discuss what happens if there is too much CO2 in tank, how to prevent CO2 overdose, and recommendations for CO2 equipment.


What is CO2 and Why is it Important for Plants?

CO2 is a colorless and odorless gas that is essential for the growth of plants. In a planted tank, plants use CO2 during photosynthesis to produce carbohydrates, which they use for energy and growth. Without enough CO2, plants cannot grow and can eventually die. Providing the right amount of CO2 to the plants in a planted tank is crucial for their health and growth.

What Happens if There is Too Much CO2 in a Planted Tank?

While CO2 is essential for plant growth, too much CO2 in a planted tank can have negative effects on the fish and plants. Here are some of the possible consequences of too much CO2 in a planted tank:

  1. Fish Can Suffocate

Fish need oxygen to survive, just like humans. When there is too much CO2 in a planted tank, it can deplete the oxygen levels, making it difficult for fish to breathe. In extreme cases, fish can suffocate and die. If you see a fish gasping for air, you should immediately check the co2 system.

fish gasping for air
  1. Algae Overgrowth

Algae can quickly overgrow in a planted tank if there is too much CO2. This is because excess CO2 can provide an abundant food source for algae, which can cause it to grow out of control. Algae overgrowth can lead to unsightly green water and can also harm the plants in the tank.

Algae in the aquarium
  1. pH Imbalance

CO2 can lower the pH levels in a planted tank, making the water more acidic. While some plants can tolerate acidic water, too much acidity can harm the fish in the tank. Additionally, a pH imbalance can also cause the plants to suffer and eventually die.

  1. Plant Damage

Too much CO2 in a planted tank can also cause damage to the plants themselves. Excess CO2 can cause the plants to become brittle and weak, making them more susceptible to disease and damage. In extreme cases, the plants can die.

How to Prevent CO2 Overdose in a Planted Tank

Preventing CO2 overdose in a planted tank is crucial for maintaining the health of the fish and plants. Here are some ways to prevent CO2 overdose:

  1. Use a CO2 Monitor

One of the best ways to prevent CO2 overdose is to use a CO2 monitor. A CO2 monitor can measure the levels of CO2 in the tank and alert you if they become too high. This can help you adjust the CO2 levels before they become dangerous for the fish and plants. When the CO2 levels reach 30 ppm, it is recommended to reduce the CO2 injection. The simplest and most reliable monitoring tool is a simple drop checker. Thanks to the reagent placed in the glass vessel, you can easily read the CO2 concentration in your planted aquarium.

  1. Use a CO2 Regulator

A CO2 regulator is a device that can regulate the amount of CO2 that is added to the tank. It can help maintain a consistent level of CO2 and prevent CO2 overdose. Be sure to follow the manufacturer's instructions when using a CO2 regulator as this is a very fragile equipment. Don't forget to visit our store and see the best CO2 regulators available on the market LINK!

pro elite co2 regulator co2art
  1. Avoid Overfeeding

Overfeeding can contribute to excess CO2 levels in a planted tank. This is because uneaten food can decompose and release CO2. Avoid overfeeding your fish and remove any uneaten food from the tank. A good rule of thumb is to feed your fish only what they can consume in 2-3 minutes and remove any excess food.

  1. Maintain Proper Water Flow

Proper water flow is essential for maintaining a healthy planted tank. It helps distribute nutrients and oxygen evenly throughout the tank and prevents the buildup of CO2. Ensure that the filter and pump are functioning correctly and that the water is circulating well in the tank.

  1. Keep the Tank Clean

A clean tank is a healthy tank. Regularly removing debris, uneaten food, and waste can prevent the buildup of organic matter that can release CO2 into the water. The cleaning crew is very welcome too. Additionally, clean water can help prevent algae overgrowth and promote the health of the fish and plants.

CO2 Equipment Recommendations

When it comes to CO2 equipment for planted tanks, it's important to choose high-quality and reliable products to maintain proper CO2 levels and prevent CO2 overdose. Here are some recommended CO2 equipment options:

  1. CO2 Regulator

    A high-quality CO2 regulator is essential to maintain a consistent CO2 level in the tank. One of the best CO2 regulators on the market is the Dual Stage Pro Elite CO2 Regulator. This regulator is easy to install and can regulate the amount of CO2 in the tank accurately.

    co2art pro elite regulator
  2. CO2 Diffuser

    A CO2 diffuser is a device that disperses CO2 into the water in the form of tiny bubbles. This helps to distribute the CO2 evenly throughout the tank, ensuring that all plants receive an adequate supply. One of the best CO2 diffusers on the market is the Inline CO2 Atomizer. This diffuser is easy to install and can help to distribute CO2 evenly throughout the tank.

    flux diffuser
  3. CO2 Drop Checker

    A CO2 drop checker is a device that measures the amount of CO2 in the tank. It can help you to monitor CO2 levels and adjust them as needed. One of the best CO2 drop checkers on the market is the CO2Art Monitoring Kit. This kit is easy to use and can help you to maintain the proper CO2 levels in your tank.

  4. CO2 Cylinder

    A CO2 cylinder is a container that holds the CO2 gas that is added to the tank. It is important to choose a high-quality CO2 cylinder to ensure that it is safe and reliable.

    co2 cylinder


In conclusion, too much CO2 in a planted tank can lead to a CO2 overdose and serious consequences for the fish and plants. It is crucial to maintain proper CO2 levels in the tank and use high-quality CO2 equipment. By following these guidelines, you can maintain a healthy and thriving planted tank for years to come. Remember to use a CO2 monitor, a CO2 regulator, and a CO2 diffuser, avoid overfeeding, maintain proper water flow, and keep the tank clean. By taking these precautions and using recommended CO2 equipment, you can prevent CO2 overdose and enjoy a healthy and beautiful planted tank.

Do you have any questions? Our expert team is always ready to answer them! Contact us directly via support@co2art.us!