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How far can you overshoot CO2 ppm?

gmanwho

Well-known member
Veteran
High all. I cycle my nat gas furnace off a relay that is controlled by a cap controller. as it calls for co2, it fires the furnace. I have a 24v fan ducted into the room that is connected to the furnace exchange box.

I dont wanna here how unsafe this is. cause its actually pretty safe as if anything failed it would not continue to fire the furnace or pull exhaust. Plus i have co monitors and a meter throughout and never had 1 alarm. Beside, i have a pretty good understand of hvac practices.

Now the monitor calls at 1450ppm. it fires the furnace and the fan. it takes on average 12 seconds to fill my 20'l x 5'w x 7' which is 700 cubic foot room. cycles about every 10-15min.

By the time the co2 reaches the controller and stops at 1550, its about 2400ppm in the room 3-4 seconds later as the co2 is being blown down the " hallway" so to say.

is a 2400ppm to much?

I would move the controller, again. but it depends on where it is , too close to the co2 fan and the controller cycles to fast.

i have NOT noticed any discoloraton on the leaves. But this is my first run at a new ebb & gro system as well, and i do seem to beleive that they may have stalled some. BUT, i did have issues with my drain pump not draining the buckets at first, so they couuld have been drowned for days unitll i found out. maybe casueing some rot. i will find out in a week when i chop.


would high amounts of co2 slow plants growth?

They look wonderful, and are as frosty as ever. but i am wondering if to high co2 is will stall the plants some?

Thanks all & b-safe
 

PuReKnOwLeDgE

Licensed Grower
ICMag Donor
Veteran
I don't run co2, but plan on installing it in January. I have done only a little bit of studying on the subject, however I do recall that fluctuations on their own are bad. Like 300ppm +/-, I think that is why some co2 controllers have fuzzy logic mode and they "learn" your room in order to maintain constant co2 ppm. I am not sure how dangerous 2400ppm is for your plants, but fluctuation could be a problem all in its own.
 

Lapides

Rosin Junky and Certified Worm Wrangler
Veteran
Yes, too high of a concentration will negatively affect your plants.

However, f the level is up to 2400ppm for just a short period of time, I don't think it will do much harm.

I had my ppms up to around 3000 for the entire light cycle for several weeks by mistake and my plants definitely didn't like it.
 

gmanwho

Well-known member
Veteran
Yes, too high of a concentration will negatively affect your plants.

However, f the level is up to 2400ppm for just a short period of time, I don't think it will do much harm.

I had my ppms up to around 3000 for the entire light cycle for several weeks by mistake and my plants definitely didn't like it.


Thats the thing, it reaches 2400 ish, then drops.to 1450 before it cycles again.

but if u think about it, call it 2500 ppm peak and 1500 ppm low. and just say every 10 mins is the cycle. so,1500 to 2500 is 1000ppm. it roughly takes 5 mins to drop 500 ppm.

that 5 min above 2000 ppm turns into 30min and hour then 6hrs in a light cycle. half its flower life of lights on is over 2000 ppm.

I think im gonna move the contoller.

And PK. i would not be able to gain the trich coverage i can without co2, 2x 3x with this one perticula stain i've been growing for almost 2 years now. co2 vs no added co2, night to day. the fluctuation has to slow, im gonna go ove and recheck all my seal areas. it has been a few years since i sealed the room. gonna try to see what i can do to get the fluctuation down more.

B-safe

so
 

guineapig

Active member
Veteran
The articles i have read say it depends upon the particular species of plant.....some plants as little as 3000-4000 and others take 10,000 ppm before the stomata begin to close and the plants health begins to decline.....

I honestly think 2400 maximum and then dropping to 1450 would not be a problem.....i'm gonna go out on a limb and say that you will be ok.....

You might want to discontinue CO2 during the last 2 weeks of flowering.....i have always seen this recommendation in the books about CO2 injection......i will try to find out the exact reason for this bit of advice, because honestly i cannot remember the reason behind it.....

:ying: kind regards from guineapig :ying:
 
S

sparkjumper

I dont know how when the level reaches 1450 and kicks in the burner,it rises all the way to 2500.I have an 8 by 8 sealed room and set my6 cap at 1500,when it drops to 1450 the burner kicks in until it reaches 1500,then it might rise another 100PPM but not like yours is doing.I dont understand that
 

gmanwho

Well-known member
Veteran
I dont know how when the level reaches 1450 and kicks in the burner,it rises all the way to 2500.I have an 8 by 8 sealed room and set my6 cap at 1500,when it drops to 1450 the burner kicks in until it reaches 1500,then it might rise another 100PPM but not like yours is doing.I dont understand that


As the first post stated my co2 is pulled off my furnace . my furnace puts out atleast 3800ppm, from what i've read on my meter. But i was told from a fellow hvac friend that any given nat gas furnace could easily reach 5000 ppm.

Much more fuel being burnt then a co2 generators pilot light or lights. A lot more.

it costs me $16 a month in nat gas to supply co2 to my room.


Gpig. i would be interested to lean who drop the co2 the last 2 weeks. HUmmmm i did see a stall kinda around 3 weeks in. they reallllyy slowed there water uptake. and then not much of a fattening up the last 2 weeks or so.

B-safe
 
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