Closed room & C02

Cultivator;3104114 said:

Ok so by doing the sealed room you dont need air exchange in the typical sense. When you ventilate a grow room via extraction and passive intake you are basically providing fresh co2 for the plants constantly, plants 'breathe' co2. imagine if you sat in a cardboard box for weeks on end and had no fresh air passing through the box you would eventually suffocate, its the same for plants.

They will be getting some co2 from the door being open and closed but that is not enough for healthy plants, add to it that its hot and RH is up and down, the plants will be stressed to the max.

The aircon will lower room temps but as you say it makes the air dry and it doesnt provide any co2 for the plants.

In a sealed room environment, which by the way is the best way to grow indoors for several reasons, you control the temperature with the AC, the RH with a dehumidifier and by adding CO2 you provide the air the plants need to breathe. Now in this scenario your room should never be too hot or too cold, RH should always be in the correct range and you can super charge grow with using optimal CO2 levels. Boosting CO2 is like putting the plants on steroids, they explode with growth. However its a pointless endeavour when running extraction as all the CO2 that is added is pulled out of the grow room before it can be used.

You need to have some sort of odour filter of it wont be long into flower that you will have the street stinking of weed. In a sealed room you hang your filter from the ceiling with a fan attached and pull air through the filter but it blows back into the grow room. This recirculates the CO2 in the grow room and addresses the odour issues.

If you dont go with a sealed room, cut a hole in your ceiling and place the duct work through the hole and extract to there via a carbon filter first.

Either way you need to find a way to exchange more air or add co2. You already have aircon and dehumidifier, a co2 generator would almost complete the room. You could buy large co2 bottles and place a regulator on it which will operate on a timer to release CO2 but you will go through a couple big bottles per week. so its cheaper to start off using bottles but more expensive in the long run over buying a CO2 generator.

If you have a CO2 fire extinguisher lying around you could manually spray the room couple times per day ad a last resort.

Click to expand...