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How to use CO² bags

Updated: Jul 21, 2023

Understanding the mushroom-CO²/ plant relationship

Mushrooms are much like humans, in that we both breathe in oxygen - and exhale CO². We are, in fact, genetically closer to mushrooms than we are plants.

Mushrooms are the grand-recyclers of earth -- without them, trees, wood and other plant material would never rot back down in to soil.

It is this recycling process of mushroom mycelium breaking down the lignins in plant matter, that produces CO² as a by-product. This breaking down of carbon-rich lignins occurs on the forest floor -- it produces CO² for the plants in the ecosystem to consume, while the plants produce oxygen for the mushrooms, making the circle of life.

Plants use CO² as one of their foods, so by providing more food we can significantly increase yields. Growth and yield increases of 20-40% can be expected -- some plant species even gaining up to 100% growth and yield increases from CO² enrichment!

Introducing the NZ-made Mushroom CO² bag!

This basic process can be harnessed with our >> NZ-made mushroom CO² bags. They produce CO² which is perfect to use in indoor grow-rooms, tunnel houses & micro-green tents. Nearly all plants growing in an enclosed environment will benefit from the extra CO² exhaled from mushroom CO² bags. It is standard practice for commercial greenhouse and hydroponic growers to supplement their grow rooms with CO².

Mushroom bags are the most natural way to generate CO². Our bags are hand-made right here in North Canterbury -- from all-NZ locally-made materials.

How to use mushroom CO² bags:

Using a >> mushroom CO² bag in your grow-room couldn't be easier: the bags arrive living and ready to go, already producing CO².

To setup the mushroom CO² bag simply align the top of the plastic bag upright -- so the white filter-patch is sitting upright and has an air-gap down to the white contents in the bag -- the CO² will be exhaled through this filter.

Sit the bag on the floor in the growing room or greenhouse, and CO² will exhale through the filter-patch into the air.

Using a mushroom CO² bag in a grow tent

Growing indoors and enclosed environments has become increasingly popular over recent years -- especially in colder regions, when it is hard to grow over winter. There are a few things to consider to get the best results out of your CO² bag.

  1. It's important to remember CO² is heavier than air so it will naturally sink to the floor. For best results it is important to have some air movement within the growing space to mix in the CO². A small fan inside the tent moving air will do this job easily.

  2. The bag can be hung from the roof of the tent allowing CO² to shower down over the canopy of the growing plants if you don't have a fan in the tent.

  3. Intense grow lights are commonly used in grow tents. The light itself is not an issue for the CO² producing mushroom, but the heat emitted from the lights can be. Be sure to keep the bags at a safe distance from the lights or heaters, so the bag ideally does not get over

28-30 deg. Temperatures above this level can begin to damage the mushroom and result in reduced CO² output.


How long will the CO² bags last?

We make CO² bags fresh weekly at the farm ensuring your bag arrives producing the highest levels of CO². Other bags on the market have to travel long ocean journeys from overseas and much of the CO² production may be lost during transit time -- this makes freshly-made local CO² bags both superior CO² producers & the best bang-for-your-buck.

SporeShift bags will produce CO² for about 4-6 months and then begin to drop off in output; they usually stop producing by 7-9 months. Peak CO² production occurs within the first 2 months.

Does temperature affect the bag's CO² production?

Yes, CO² output can be influenced by temperatures.

For example, a mushroom bag exhaling CO² in an average temperature of 25deg will produce more CO² in a shorter period of time but will cease CO² production earlier. The opposite is true for a bag in a cooler environment: a bag in an average temperature of 10deg will produce CO² at a slower rate for much longer.

How many CO² bags do I need?

There is no absolute answer for this as there can be many variables that affect CO² levels in a grow room. e.g. fresh air flow, stage of plant growth, size of plants, number of plants etc.

However, we do have some rough guidelines you can follow, these guidelines will work for grow tents, glasshouses/ tunnel houses or any enclosed growing environment:

Ambient atmospheric CO² levels are around 420ppm at present. Greatest plant-yield and growth improvements are achieved in the 1000-2000ppm range.

I will base the example on one of the more common size indoor grow tents -- the 1200x1200mm size. We recommend 2-4 bags in a 1200x1200 grow tent -- so if your tent is twice the size then you'll need twice as many bags etc.

Another way to calculate the bags needed, is to work out the floor space of the grow space in M² (the grow area's base-width X base-length to get M²), then multiply the M² x 2.77 to give you the number of bags needed for your grow-area floor space.

Math example for the 1200 x1200mm (1.2m x 1.2m) tent size/ floor area:

  1. 1.2m x 1.2m = 1.44m² floor space

  2. 1.44m² x 2.77 = 3.988

  3. Round 3.988 to 4: so we need 4 bags for this size tent/ floor area.

Math example of a 1200x2400mm (1.2m x 2.4m) tent size:

  1. 1.2m x 2.4m = 2.88m² floor space

  2. 2.88 x 2.77 = 7.977

  3. Round 7.977 to 8: so we need 8 bags for this size tent / floor area.

The math example above is calculated by using a ratio of 4 bags in the 1200x1200 tent size, if you wish to calculate it based on 2 bags for this area then use 1.385 instead of 2.77

How do I get constant CO² supply in the grow room?

Now that we understand how the bags releases CO², and how many bags we will need for our grow space, we can make a plan to achieve steady elevated levels of CO² in our grow room with a simple bag rotation plan. Each bag comes with a batch number and manufacture date on it: you can use this to keep track of how old bags are within your setup.

Example of a simple CO² bag cycle

  1. Use above math formula to calculate how many bags you will need for your grow area (we will call the number of bags needed X for this plan).

  2. Start with X number of bags in the grow room. (1st batch of bags)

  3. 8-10 Weeks later put in X new fresh bags. (2nd batch of bags)

  4. 8-10 Weeks later when your 3rd batch of bags arrive the first batch of bags will be 4-5ish months old, they can be removed and contents composted. The plastic bag should be disposed of in rubbish or soft plastic recycle. (Using the dates on the bags you can keep track of how old the bags are and cycle new batches of bags in as the old ones finish).

  5. Simply continue this rotation to keep fresh high-producing CO² bags coming in as the old used bags are rotated out.

  6. This rotation will give the best CO² levels possible. You can also rotate every 12-16 weeks or 16-20 weeks for a more economical rotation, but somewhat lower CO² levels will be achieved on average.

How much more yield can I expect with the CO² bags?

  • Plants grown in CO² levels around the 1000-2000ppm range have reported yield increases anywhere from 20-40%. (Which explains why most commercial glasshouse growers supplement their plants with CO²)

Do I need to do anything to maintain the bag?

  • No, the CO² bags come ready to go -- they do not require any maintenance once in the grow room.

Do CO² bags produce heat?

  • CO² bags will not produce any heat that could cause an issue in the growing environment.

How does the CO² get out of the bag?

  • There is a specialised white filter-patch on the front of the bag which allows the bag to exhale CO² and draw in oxygen.

What is the liquid forming inside of the bag?

  • Mushrooms are water lovers, the contents of the bag is a hydrated carbon-material-mix containing water: as the mushroom mycelium breaks down the material inside the bag, converting it to CO², a clear-to-yellow liquid will pool inside the bag as a by-product. This is natural, healthy and harmless and does not need to be drained. If the bag does leak you can simply wipe it up or leave it to naturally evaporate/ soak into the soil.

  • It is best to keep the bag sealed so moisture does not evaporate out of the bag too quickly. If holes are made in the bag the water in the carbon mix will evaporate and CO² production could stop prematurely. If you do accidentally put a hole in one of your bags simply seal it with some plastic tape or duct tape etc.

Do I need to worry about bugs, pests or diseases from the bag in my grow room?

  • The contents of the bag are 100% steam-sterilised during manufacture -- there is no chance of introducing harmful bugs, pests or diseases to the growing environment.

Will the mushroom CO² bag grow mushrooms?

  • It's important to keep the bag sealed so mushrooms do not try to grow outside of the bag. You will get some white hard growth on top of the white block inside the bag as it ages and the mushroom mycelium grows upward -- but as long as the bag is kept sealed mushrooms will not grow outside of the bag.

My mushroom CO² bag isn't white anymore?

  • As the bag ages the mushroom mycelium inside the bag will also age, harden, and change colour. Orange to yellowish colours are normal as the block ages. (If your block goes green - or any other irregular colours - please send us a photo with the batch number and we will organise a replacement/solution).

What are the ingredients in the bag?

  • The material inside of the bag is a SporeShift proprietary blend of carbon-rich material and locally-sourced, mushroom nutrient-mix. It is a matrix of rapid-break-down nutritional food, and a slower decomposing carbon-rich food source for the mushroom. This mix gives a large burst of early CO² release followed by a slower longer release. The carbon matrix is sterilised and then our in-house CO² producing culture is added.

Is the CO² produced bad for the environment?

The carbon mix we use is made from waste material so whether we use the mushroom to break it down or just allow it to break down naturally, the carbon from the mix will be released either way. In fact, by capturing this carbon in our mushroom bags and utilising this carbon resource with our plants the carbon can be used as food and stored in the plants, therefore helping to reduce and re-store the carbon!

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