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Introduction to CO₂ Enrichment

CO₂ Enrichment has the potential to increase the growths of your plants by 25-40%!  To the left are links to information on CO₂ enrichment.

What Does CO₂ Do?

CO₂ is a vital component in the process of photosynthesis. During photosynthesis, light interacts with CO₂ and water to form complex sugars, which are then processed during the night time (or when your grow lights are turned off) to form natural polymers for growth. To ensure that your plants can grow it is important to make sure that your plants have a constant supply of CO₂. If you are growing your plants indoors, there are two ways to ensure a constant supply of CO₂. The first is to make sure the room is well ventilated, the second is to inject up to 1600 ppm (parts per million) of agricultural grade CO₂. The second method will provide by far the greatest results.

How Much Difference Does CO₂ Make?

The positive effects of increasing the concentration CO₂ into your growing environment have been widely documented in agricultural research journals. Depending on the quality of your CO₂ injection system, your plants will increase their growth by 25 - 40%. Other benefits include, increased number of flowering and budding sites, increased stress resilience, improved nitrogen fixation and increased water efficiency.

Are Fans Important?

Yes, especially for large grow areas! When your lights are off CO₂ is not utilised by plants, and so it is important to circulate oxygen (which is required by plants) into the room. It is important to remove excess CO₂ as levels above 2000ppm are toxic to your plants. .Fans are also beneficial when used whilst your lights are on. Most CO₂ controllers have fan controllers which will quickly remove hot air and/or excess CO₂ which have built up in your grow room. If your controller does not have this, then temperature activated fan controllers can be purchased separately or simply set your fans to run on a fixed time cycle which you know will effectively remove hot air and excess CO₂.

Air should be circulated through your grow room at a rate of five times per hour (if your room is 20 m³, then you need a fan rated for at least 100m³). Ideally your set up will include two fans. One fan, the induction fan will be set up low down at one corner of your grow room, and the other fan, the exhaust fan will be set high up in the opposite corner.

Methods of Injecting C0₂ Into Grow Rooms

Depending on the size of your grow room, the Hydroponic Warehouse recommends three types of injection systems. For larger grow rooms we recommend controlled injection via a pressurised gas bottle, using the Compugas CO₂ Controller. For smaller grow rooms we recommend the.  All of these products are carried by the Hydroponic Warehouse (though they do not appear in our catalogue).  Please contact us if you are interested.

Injection via A Pressurised Gas Bottle

If you are injecting CO₂ into your grow room via a pressurised gas bottle then you will need to plan ahead a little. Gas bottles can be rented from BOC (ph# 131262 Australia wide). Monthly hire of gas bottles is about $10*, though this must be paid one year in advance. Refill of a large gas bottle will cost about $25 and this should last about a month for an average sized room. FOG grade gas should be used as this is designed specifically for horticultural use. Once you have arranged your gas bottle you are ready to purchase your CO₂ controller.

*Prices mentioned here are based on current Australian prices and are an estimate only.

The Hydroponic Warehouse
Shop 3, 73 Pickering Street, Enoggera
Brisbane QLD Australia
(Opposite Enoggera Bowls Club.)
Phone: +61 (07) 3354 1588 Fax: +61 (07) 3354 3622