You want to increase your yields, but don't know how?
A good method to achieve a successful harvest is CO2 fertilisation. Cannabis plants need CO2 to live. A high CO2 level in the air can accelerate the growth of your plant and lead to a high-yielding harvest. Why CO2 is important and how you can increase the CO2 level in your grow room can be found here in our article on CO2 cannabis grow.
Table of contents
What is CO2 and how is it measured?
CO2 is an odourless and colourless gas composed of one carbon atom and two oxygen atoms and is also known as a greenhouse gas. However, it is vital for plants. CO2 is measured in the unit ppm (parts per million). The value indicates how many molecules of CO2 per million molecules are found in the air. Outdoors, the CO2 value in the air is around 350-400 ppm.
Why do cannabis plants need CO2?
CO2 is important for the process of photosynthesis and thus also for the growth of your cannabis plant. When a plant performs photosynthesis, it converts the CO2 from the air into sugar and oxygen. The plant uses the sugar as a source of energy for its growth. It therefore stands to reason that your plant needs CO2 for healthy growth. If the CO2 level in the air is too low, this can have negative consequences for plant growth.
Especially if you want to grow cannabis in a grow box or grow tent, you have to make sure that your plant is supplied with enough CO2. If you use the CO2 fertilisation method, there are some advantages. You will find out what these are in the next section.
What are the advantages of CO2 fertilisation in the growroom?
If you are growing indoors, it is advisable to increase the CO2 concentration in your grow room.
As already mentioned, the CO2 content in the grow environment should be relatively high so that your plant can grow healthily. Generally speaking, a high CO2 concentration promotes fast plant growth. By adding CO2 you can shorten the vegetation phase and flowering time of your cannabis plant.
A high concentration of CO2 in the air not only leads to rapid growth, but can also increase your yield and harvest.
The CO2 cannabis grow also has the advantage that your plant is able to use the light from the grow light more efficiently when the CO2 content in the air is high. This way you can save on electricity costs!
CO2 can also enhance the size and quality of your plant's buds. If your cannabis plant grows in a CO2-rich environment, the flowers are likely to have a higher THC content.
Increasing the CO2 level in your grow room can also have the advantage of reducing stress on your cannabis plant. This is because your plant has enough CO2 available for photosynthesis and therefore needs to evaporate less water to absorb CO2. It is also able to withstand high temperatures due to a good CO2 supply.
How much CO2 to use for CO2 cannabis grow?
For healthy plant growth, a CO2 concentration of 350-1500 ppm is optimal. If you are growing in a growbox or grow tent, we recommend a value of 1000-1500 ppm. However, the ideal CO2 level ultimately depends on several factors such as the size of your growroom, the number of plants you have and the type of grow lighting.
When growing CO2 cannabis, you should be aware that too much CO2 in the growroom can also have negative consequences for your plants. Therefore, you should check the CO2 concentration regularly to achieve good results and ensure healthy plant growth. If your plant looks weak or takes on a yellowish colour, this can be an indication of too much CO2. In this case you should stop the CO2 fertilisation.
To measure the CO2 concentration in the growroom, you can use a CO2 monitor or a CO2 sensor. This way you can prevent your cannabis from being supplied with too much or too little CO2.
When should CO2 be used?
Cannabis plants need a lot of energy for their growth during the vegetation phase. In this phase, a high CO2 concentration in the air can support and accelerate growth. Also in the flowering phase of your cannabis plant you should increase the CO2 content. Producing flowers requires a lot of energy from the plants. A high CO2 content in the air can promote the formation of large flowers.
As your cannabis is photosynthesising in the light phase, we recommend increasing the CO2 concentration during this time. In the dark phase you can do without CO2 fertilisation, as cannabis cannot absorb CO2 during this time anyway.
CO2 Cannabis Grow - CO2 systems for the grow box
If you want to increase the CO2 concentration in your grow box or grow tent, you can do this in several ways.
On the one hand, there are CO2 bags, that you can hang in your growroom. You can find these in our Bonsanto shop, for example. They are quick and easy to use and last about 2 weeks.
CO2 generators can also be a good way to increase the CO2 content in your grow box. They are usually easy to operate and can be combined with a Timer so that the release of CO2 is automatically regulated. From summer 2023 you can find a tablet-powered CO2 generator in our Bonsanto Shop! It is a bit more expensive to buy than the CO2 bags, but it is cheaper in the long run, as you can fill it with inexpensive CO2 tablets.
What should I pay attention to when fertilising with CO2 in the grow box?
If you want to implement CO2 fertilisation in your grow box, there are a few things you should pay attention to.
To ensure that the CO2 really gets into your grow room and that your plant can benefit from the CO2, you should seal your grow box or grow tent well. If you use a Bonsanto grow tent or one of our grow boxes in combination with the Bonsanto CO2 bags or the CO2 generator Grow, you have the advantage that you can attach both the bags and the generator inside and then close the tent or the box with the zip. This way, your grow room is automatically well sealed and the CO2 can be absorbed by your cannabis plant.
For your plant to absorb CO2, it needs to be well lit. Therefore, when growing CO2 cannabis, make sure that your cannabis plant is sufficiently lit in the grow room.
As CO2 has a higher density than air, it falls to the bottom. Therefore, we recommend that you mount your CO2 system at the top of your grow box or grow tent so that your cannabis plant gets some of the CO2. If you prefer to place it at the bottom, you should use a fan to circulate the air so that the CO2 is distributed throughout the growroom.
CO2 Cannabis Grow at a glance
- A high CO2 content in the air promotes the growth and harvest of your cannabis plant
- When growing in a tent or grow box, we recommend a CO2 level of 1000-1500 ppm in the air
- Use CO2 fertilisation during the vegetation and flowering period of your cannabis plant and during the light phase
- For CO2 fertilisation you can use CO2 bags or a CO2 generator
- The Bonsanto CO2 Generator will be available in our shop from summer 2023
- Make sure you have a sealed growroom if you want to increase the CO2 content in the growbox
- Place your CO2 system at the top of the growroom or provide recirculation
- If you want to use the light of your lamp efficiently, you can equip your growbox with a Bonsanto reflection foil ausstatten.