Proper Application of Co2 in Hydroponics


When plants grow in soil outdoors, they naturally receive sufficient amounts of C02. However, in indoor hydroponics, your plants aren’t naturally exposed to the same amounts of C02. This means that C02 will need to be added to your hydroponic system in order to support the best growing conditions desired by your plants.

Before deciding you need to add Co2 to your system, you should ensure that all other growing conditions are in tip-top shape. This means proper lighting, ventilation and airflow, spacing between crops, and the current nutrient levels all working together in your system. If none of those conditions are properly established, then adding C02 will be a waste as the plants are likely strictly in survival mode.

How to Measure Levels of Co2 in Hydroponics Systems

In order to determine whether or not you even need to increase Co2 levels in your hydroponic garden you will need to take a measurement. Measuring the levels of C02 in hydroponics is an important step in ensuring your garden is functioning at its optimal levels. To measure the levels of Co2 in hydroponics, the more intermediate to advanced grower can use a Co2 monitoring system. These units measure the amount of of Co2 in ppm (parts per million) which is the unit of measurement for carbon dioxide. Co2 controllers and monitors can be purchased at your local hydroponics or indoor gardening supply store. You can also order them online from The average or recommended levels of Co2 in hydroponics systems should be between 1,000 and 2,000 ppm.

For beginners you may alternatively want to use this Co2 calculator which will indicate estimated Co2 levels based on the size of your grow room and other factors.


Active Air Co2 System maintains Co2 levels for indoor gardening. Image via

How to Increase Levels of Co2 in Hydroponics Systems

After measuring the levels of Co2 in your hydroponics system, you will know whether or not it needs to be increased. If your Co2 levels are below the recommended average then you can boost carbon dioxide with Co2 enrichment methods. There are Co2 monitoring systems available which will automatically boost Co2 levels if they fall below a certain ppm level. These units can also be put on a timer so that they only dispense C02 during the day/lighting cycle as this is, of course, the time when photosynthesis occurs.

Read more about Co2 enrichment methods for small, medium, and commercial sized grow rooms.Feature Image: Proper Co2 levels in your hydroponic garden, produce deep green leaves on your plants. Image via Food Wise.

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