[Salami]

Hey all,

Question on CO2..

I have a 10*14 foot cellar with 2 meters of headroom.  In there, I currently have a mum/clone cupboard,  a 120*120*196 (had to shorten the poles) budbox with 4 individual scrogs, and a 1 meter square area sectioned off for vegging.

I'm getting another tent (same size) and am building a little mum/clone/early veg area in the sectioned off bit.  Looking to have a perpetual grow on for a while. 12ish plants (4 vegging, 4 early flower, 4 late flower), with a 50 cm scrog canopy.

The tents and veg cab have/will have ample air exchange (quality RVK), but the cellar itself doesn't have any fresh carbon dioxide aside from what I breath out and whatever creeps down the stairs while I'm down there..

Should I:

A. Not worry.
B. Sort out cycling the air in the cellar with:
  I.  House air
  II. Outside air
C. Create CO2 with:
  I.   Tablets
  II.  Organics
  III. Some other method

I'm going to read up on symptoms of low CO2, but I'd appreciate firsthand info, if you have it..

All knowledge gratefully received

This post has been edited by Salami: 26 May 2012 - 08:27 PM

[reg llama]

if your extracting out of the cellar (yopu should be or damp will be along shortly) what gets took out just gets replaced with fresh air passively through whatever nook or cranny it can get through, the new air will have all you need.

from what i remember using co2 requires some kind of sealed room set up

[ZedBud]

B1 or B2 for me

Nice supply of intake air is an important factor in getting your environment right. I'd imagine low CO2 would slow photosynthesis and thus slow their growth/development somewhat.

Could you add a vent into the cellar? Maybe just a PC fan drawing air from inside the house somehow?



Z.

edit: Am I right your extracting into the cellar space from your tent?

This post has been edited by ZedBud: 26 May 2012 - 08:40 PM

[distracted]

B and only B.....photosynthesis mainly needs light, CO2 and water, restrict any and something will suffer. Air circulation from anywhere is required... get fresh air into the room or cellar then clean the air through a carbon filter and vent it along with the heat

[Salami]

I'm not (at the moment) extracting out of the cellar.

Its a hundred plus year old house and the cellar is concrete floor, bare brick walls & floorboards up top. It's naturally a bit damp down there, which is why I'm using tents / cabs. I've found that I can control the environment in the tents enough to eliminate (or at least drastically reduce) the risk of mould.

The money I'm saving by not having to buy weed is going into my "Tank & Dexter's Lab the cellar" fund

E2A
I'm extracting from spaces (thru filter where appropriate) into the cellar ATM.

This post has been edited by Salami: 26 May 2012 - 08:50 PM

[distracted]

if you think you are handling the temps OK while running it as a closed system then you may be able to add CO2 as it won't get pissed away... I posted the calcs for co2 emission from fermentation and also bicarb on here but can't remember where...

[Salami]

I'm happy to go with venting out of the room into the house or outside (assuming this would be preferable to sucking fresh air in.?)

Just as happy to have a stab at introducing co2, so I'll see if I can dig up those stats you mention and have a read..

[SickLeaf]

Dont forget that plants use oxygen and give off CO2 at night. If you are using multiple tents then get the lights on/off periods flip flopped so the plants in the dark provide CO2 for the ones in the light and vice versa the ones in the light provide oxygen for the ones in the dark.

[Salami]

SickLeaf, on 26 May 2012 - 09:45 PM, said:

Dont forget that plants use oxygen and give off CO2 at night. If you are using multiple tents then get the lights on/off periods flip flopped so the plants in the dark provide CO2 for the ones in the light and vice versa the ones in the light provide oxygen for the ones in the dark.

This I did not know.. given the two tents will be on 12/12 for most of the time, is it an equal flipflop..? The same amount of each produced/consumed over the light/dark cycle..?

[Salami]

A spot of Googling answers that as a no.

Not enough co2 is given off at night to sustain photosynthesis during the day. I'd suspect that applying more so to us, as we're hammering as much light as we can at them..

See. This is why I love this stuff. I get baked AND I learn shit.

This post has been edited by Salami: 26 May 2012 - 11:45 PM

[SickLeaf]

I did a bit of googling after about terrestrial plants. Like you say its not an equal like for like swap but every little helps. I know de-oxygenation is a big problem on weed choked lakes (eutrophic) at night so thought it was worth a mention out of curiosity.

This post has been edited by SickLeaf: 27 May 2012 - 01:28 AM