Due to business restructuring, we are currently not accepting any new orders.

CO2 Bag Generator

4.89 out of 5
(9 customer reviews)

£15 (incl. VAT)

Continuous natural supply of carbon dioxide for your plants. Utilising the natural properties of mycelium which colonises the organic bag contents whilst at the same time expelling copious amounts of pure CO2 as a by product. Mycelium Grows: CO2 Flows!

Generating CO2, 24 hours a day for 4-6 months our CO2 bags are more than twice the size of exhale bags and the largest CO2 generating bag on the market. Each bag can cater for up to 10 large plants or a growing environment of up to 35 square feet (or larger with less ventilation).

Similar to MyCO2 & Exhale bags but with the following differences:

  • We’ve tested our bags and found they give the highest total CO2 output of any CO2 bag on the market
  • Made to order on day of shipping so no wasted CO2
  • We use supplemented organic hardwood as the growing medium, which has the highest calorific value mycelium will grow on, this means, higher CO2 output for a longer and sustained period.
  • A slow growing, none-fruiting mushroom strain is used for consistent CO2 output
  • We’re in the mushroom production game, we make 100’s of these bags on a weekly basis which is why we can offer them at competitive prices without the high markup

Made to order in the UK on the day of shipping, so no wasted CO2 as it sits there in storage like most other brands.

SPECIAL OFFER: Buy 2 Bags for £30. Save £10. Limited time only.

No setup. No maintenance. Works 24 hours a day. Completely natural and easily recyclable. Don’t pay extortionate rates for a brand name which offers inferior CO2 production. We guarantee our CO2 bag generators produce more pure CO2 than any other bag on the market (We’ve tested them all!), and because each one is made on day of shipping, you benefit from all the CO2 the bag has to offer!

Guaranteed to improve the growth and health of your plants.

Odour free, no heat produced, no electricity required. A completely safe and low cost way to boost CO2 levels in your grow room without expensive equipment or dangerous propane burners. Can increase yields by 20-50%. Shipping is free and is delivered in discreet packaging.

Discreet Shipping as Standard

Free Delivery on all orders over £40.

£15 (incl. VAT)

SKU: co2-bag-generator Category: Tags: ,

Frequently Bought Together

Unique micro-porous filter strips to regulate the flow of CO2. Perfect for indoor our outdoor grow rooms. Carbon Dioxide is often considered to be the ‘missing nutrient’ and is perhaps more important than lights and nutrients. Plants have the ability to utilise 1500ppm of carbon dioxide for optimised growth, but with typical indoor CO2 levels of ~350ppm, you can see how this is far from optimum. Plants breath in CO2, and with inadequate amounts, your plants and harvests will suffer. Our bags will release approximately 1000-1500ppm of carbon dioxide.

In a vented room, bags are best placed on the floor next to the base of the plants. This way all generated CO2 is pulled through the canopy, directly over the plant leaves. In unventilated rooms, bags can be placed anywhere in the room. If not using straight away, you can place in refrigerator for up to a month to stop mycelial growth and delay CO2 production. Can be used for both vegetative plant growth as well as for fruiting and flower production.

Our CO2 generating bags will first start out brown, but will eventually turn white as the mycelium colonises the bag contents. Once fully colonised, it is normal for the bag to develop a yellow (or other coloured) liquid and for the bag contents to change another colour. The changing in colour happens as a result of the mushroom mycelium colonising and digesting the organic bag contents.

If using the bag in a greenhouse, ensure the bag is kept out of direct sunlight.

Make sure to never pierce the bag as this could potentially contaminate the bag contents with mould spores.

After CO2 levels stop, you can compost the bag contents, the bag itself is made from Polypropylene, which might also be recyclable depending on your local regulations.

Effects of CO2 on Plant Growth

Why is Carbon Dioxide Important?

9 reviews for CO2 Bag Generator

  1. 5 out of 5

    Steve P

    no problems, well packed, now a week into colonising so can see growth and PPM meter for CO2 shows 800-900 but I do have ventilation so fine with that. was at 380ppm before. plants dig it cant wait until harvest

  2. 5 out of 5

    Dan Dan The Man

    Simple concept and it works. Every one should use one of these. seems like a reputable company so happy to support

  3. 5 out of 5


    cheaper than the rest and they are bigger and better does take a few days to start CO2 off but would rather that that have a half colonised one with a shorter life span. great job A++++

  4. 5 out of 5

    Stephen s

    Initially I thought I got a duff bag as little co2 was being produced, I contacted Paul who outlined that the bag was made fresh on day of dispatch and that CO2 would start increasing in the next couple of days, which, it did. 3 weeks in and still going strong, it's a pretty big bag, I have 2 grow [email protected] roughly 2m x 2m dims, noticeable vitality and enhanced grow on the one with the bag in.I usually dont leave reviews but company was so helpful and product works that wanted to. thanks Paul & the team

  5. 5 out of 5


    cheapest way for me to increase co2 in my grow room I placed bag on floor as recommended and seems to do the trick

  6. 5 out of 5


    was dubious at first but have co2 meter these things really work 3 months in and stil producing co2 salad leaves love it cheers bro

  7. 5 out of 5


    first class service as always fast delivery

  8. 4 out of 5

    field of green

    my co2 moniter confirms they work and spout out quite a bit of co2 but I've got a pretty hefty ventilation system so not sure if it's all going out the roof? no detrimental effects to plants, not sure if the beneficial results are placebo or not?

  9. 5 out of 5

    Dr D. Williams

    works as it should. I've used the popular exhale bags, but they are produced in the USA, then shipped over to the UK, then sat in a distribution hub, then on a store shelf. By this point, weeks or months may have elapsed. I purchased the one on this site and it looked completely different. Then after about 4 days I started to see white spots appear throughout the bag, 2 weeks later, the bag is completely white so you know you're getting maximum CO2 output.

    From browsing the site, I can see that they are in the mushroom game so it's probably easy for them to produce these.

    Final thoughts: the product works well, bigger and better than any other one I've ever used and lasts more than twice as long. Do the tests yourself if you're not convinced.

    Peace out all

Add a review

Additional information


1, 2 – Save £10

Free Mushrooms

100% FREE Mushroom Giveaway


FREE P&P | No Purchase Necessary | One Per Household.

Send Me Some Mushrooms!

Free Mushroom Selection Box

A selection of our finest organic dried mushrooms

No catches, we'll send one to you a dried gourmet mushroom selection box for free, we'll even pay the postage.
Why are they free? We just want to let you sample our mushrooms, if you like them, (which we're sure you will!), you might want to buy some more from us in the future.