Grow Room Co2 WHAT TO BUY

[Builder0101]

Yes my research suggests bigger faster veg with Co2 and lots of growers use Co2 for veg only. I have a perpetual grow. I will be harvesting 3 plants every 2 weeks. I really don't need the Xtra work and expense of Co2. I'll be buried with trimming and curing and training...

 

[Death The Cultivator]

Yes my research suggests bigger faster veg with Co2 and lots of growers use Co2 for veg only. I have a perpetual grow. I will be harvesting 3 plants every 2 weeks. I really don't need the Xtra work and expense of Co2. I'll be buried with trimming and curing and training...

I looked at c02 last year and came to the same conclusion. The cost of c02 is high compared to a larger space and supplemental lighting.

@Bigg Al If it isn't sealed or connected to a regulator then I wouldn't know if it was beneficial or being wasted. Since it cany be controlled, c02 would be in excess at night when the Calvin cycle occurs. During the day with active extraction there is still the mystery of how much is being used/needed.

 

[Builder0101]

I did the math a long time ago and I think a bottle of yeast and sugar water raised a 4x4 by environment+50 or so. I had 6 gallons going for a while. It was pretty cheap. Pain in the ass

 

[JSH1973]

I just keep a couple of cows in my tent... Best Co2 supplement you can get

 

[Mañ'O'Green]

IMPO Unless you have a closed and sealed room it is a waste of time and money. The numbers crunching I did found the break even point at 24 plants, I can only grow six! This assumes a 20% increase in harvest. Electricity at .28/kWh and wholesale price of flower at $1800 a pound.

For small grows the bags are a problem because they give off gas at night when you really don't want it. Just buy better lights with the money.

I am on target to get 750g/m² in my just finished grow. The last plant is drying right now. This is huge and I think it has a lot to do with my new ChilLed Growcraft lights. I need to get a few more grows completed with them before making any conclusions but it is looking good.

 

[Arthur]

CO2 will change your girls feeding habits as well. So be prepared to up your feeding schedule!

 

[WildBill]

Watts per square foot is Bro-science and has nothing to do with the spectrum and PPFD provided to the plant. The DLI (daylight integral) is the number of PPFD presented to the plant over a day. This is the science you want to look at. Cannabis performs best with 28 - 32 DLI as a minimum and will utilize up to 60 DLI but there is a diminishing return on the light over 50 DLI. Unless you are using Co². You want your lights to be full spectrum. That used to mean PAR (photosynthetic active radiation) 400nm to 700nm wave length light but new science is extending that from 350nm to 750nm.


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The green in the middle has now been proven to be used by the plant as well as ultra-violet 350nm to 400nm as well as far red 700nm to 750.

Most commercial lights do not include the ultra violet (or enough) but can be added with other sources later. Many lights do now include the far red.

This spectrum is Blue heavy and will be better for the vegetative cycle:

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While this leans red heavy and is better for Flowering.

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Many lights allow for different spectrum by turning on or off or otherwise adjusting the spectrum.

Reputable Light manufacturers will have this information for you. You may need to do a little math to compare fixtures but here is what I feel you should look for in PPFD.

The PPFD (photosynthetic photon flux density a measure of the photons) foot print can be a shortcut to visually find a good light once the spectrum is correct. They look like this. It gives you the PPFD for a given area at a given height. You are looking for ~1000 PPFD in the center and as much as you can get on the outsides. 1000PPFD will produce about 32 DLI in 18 hours. If running C0² you want up to 1500 PPFD.


View attachment 1258910


Two fixtures with close spectrum and PPFD can have drastic differences (efficiency) in the watts used to produce the same light. This is why watts per square foot is Bro-science.

Link for more DLI info and scroll down for an easy DLI calculation.

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I think I'm gonna test my grow room all closed off to see what the temps will tend to run and see where I need to be on the relative humidity on the VPD chart. The temps should be pretty stable if I can maintain the house temp. It has two exterior walls, but they have lots of insulation and with my wrap around porch no direct sun can hit the wall with the porch overhang and the attic above the room has LOTS of insulation.
Without building a dedicated growroom with it's own A/C, this would be the only time of year I could possibly use CO2.