Stoping Co2 Two Weeks Before Harvest Question!

[3 balls]

Yes its not desirable to promote high rates of growth when the plant stretches because the aim is to reduce stretch and not to encourage it.

It makes complete sense, I mentioned it because although it makes all the sense in the world, nobody I know has put two and two together on that one. Great stuff!

 

[Glow]

Yes also on the point of this thread I would absolutely recommend that you didn't elevate CO2 in the last two weeks. Its simply a waste of quite costly gas. I.e. the rate of photosynthesis/cell division in the last two weeks is about nil so giving the plants more CO2 which is assimilated in photosynthetic processes is pointless.

 

[HappyMonkey]

Awesome, I read most of the topics but have trouble scrolling down that page. Thank you

Check this out Happymonkey

@Glow Thank you both a whole bunch !!!

 

[HappyMonkey]

Yes its not desirable to promote high rates of growth when the plant stretches because the aim is to reduce stretch and not to encourage it.

I could not agree more! Thanks for taking the time to answer us, much appreciated!

 

[HappyMonkey]

@Glow @3 balls

The CO2 redelivery system under the plants on your site is smart thinking : )

 

[Kot]

If you are in sealed room like me you should not stop it cause the plants will use all the CO2. I lower it to 800 PPM in the last 2-3 weeks.

btw don't know how it is expensive gas when it costs me 20 bucks to fill a 20 lb tank which lasts me months.

 

[Glow]

If you are in sealed room like me you should not stop it cause the plants will use all the CO2. I lower it to 800 PPM in the last 2-3 weeks.

btw don't know how it is expensive gas when it costs me 20 bucks to fill a 20 lb tank which lasts me months.

Yes sorry in a sealed room where you can't exhaust air you need to keep CO2 injection happening although I think you'd find 400 - 500 ppm would suffice. A lot of CO2 rooms are also vented using baffles on fans to create seals so that gives the grower the option to vent also or run an entirely sealed room.

 

[Kot]

Yes sorry in a sealed room where you can't exhaust air you need to keep CO2 injection happening although I think you'd find 400 - 500 ppm would suffice. A lot of CO2 rooms are also vented using baffles on fans to create seals so that gives the grower the option to vent also or run an entirely sealed room.

I have big problem with heat and height. That's why I keep it 800.

 

[1diesel1]

When I had my completely sealed grow weeks 3,5,7 the plants would intake the most co2 during growth cycle. They would suck down 3/4 of a 50 # bottle each of those weeks at 1200 ppm. After week 7 I always shut off co2 system.

 

[Glow]

When I had my completely sealed grow weeks 3,5,7 the plants would intake the most co2 during growth cycle. They would suck down 3/4 of a 50 # bottle each of those weeks at 1200 ppm. After week 7 I always shut off co2 system.

Yeah I haver always found most genetics max out at 1150 ppm. After that there doesn't seem any benefits in giving them more CO2.

 

[3 balls]

Yeah I haver always found most genetics max out at 1150 ppm. After that there doesn't seem any benefits in giving them more CO2.

I'm thinking it would be worth upgrading my current controller that has 1000,1250 and 1500 as the only options to a digital. I'm thinking 500 thru 2.5 weeks to control stretch, then 1150 until the final 2 weeks when I dial it back to 500. Sound about right? This would be a semi specific formula for me- sealed room with height limitations.

 

[Glow]

I'm thinking it would be worth upgrading my current controller that has 1000,1250 and 1500 as the only options to a digital. I'm thinking 500 thru 2.5 weeks to control stretch, then 1150 until the final 2 weeks when I dial it back to 500. Sound about right? This would be a semi specific formula for me- sealed room with height limitations.

Yep with CO2 you want your controller to have full control so you can set any ppm. Also you want it with a sniffer so it automatically regasses to your desired CO2 ppm optimum that you set. If you are in a fully enclosed environment those figures sound okay although really in stretch and in the last two weeks I'd even go a bit lower to about 350 - 400 ppm which is pretty much what you find outdoors in nature (although this one can be highly variable and is influenced by a bunch of factors)

 

[Kot]

Spurr, if you rember/know him, found research that 1200 PPM is the max you should be using.

My CO2 controller is from co2meter.com and is running pretty good 7th month now.

 

[Glow]

Spurr, if you rember/know him, found research that 1200 PPM is the max you should be using.

My CO2 controller is from co2meter.com and is running pretty good 7th month now.

Yes I do remember him. Didn't always agree with his information but 1150, 1200 ppm. Either way is just fine.

 

[dorjewright]

Great Info; But what about co2 and vegging. That's where I'd like a hurry-up. 18/6 x 4 +/- weeks is a lot of electricity/cost.
Another reason I like co2 in a sealed room is I can run higher temps which solves some of my cooling problems without an air conditioner.
I'm just beginning another run with 6 DHN clones (Blackjack and Midnight Splendor). I logged on to Farmer this morning looking for more info on co2 so I greatly appreciate this thread. The last grow (24 girls) I settled on 1000-1200ppms co2 / 82F but had one variety hermi and polinate all the others before i discovered it (still some great smoke though). I'm thinking the temp as the cause. My now plan is 1000ppm/80F.
I would sure like to shorten the veg time. But I would like to hear about co2 and vegging.

 

[Kot]

I have not found any info on CO2 during veg so I use 800 PPM in veg and 1100-1200 max in flowering.

 

[3 balls]

Great Info; But what about co2 and vegging. That's where I'd like a hurry-up. 18/6 x 4 +/- weeks is a lot of electricity/cost.
Another reason I like co2 in a sealed room is I can run higher temps which solves some of my cooling problems without an air conditioner.
I'm just beginning another run with 6 DHN clones (Blackjack and Midnight Splendor). I logged on to Farmer this morning looking for more info on co2 so I greatly appreciate this thread. The last grow (24 girls) I settled on 1000-1200ppms co2 / 82F but had one variety hermi and polinate all the others before i discovered it (still some great smoke though). I'm thinking the temp as the cause. My now plan is 1000ppm/80F.
I would sure like to shorten the veg time. But I would like to hear about co2 and vegging.

In my veg, I'm stuck with temps in the mid 80's. The best I understand everything I've read, high end VPD/RH is the best I can do to combat those temps. My understanding of @Glow literature is RH over 55% negates the benefits of CO2 enrichment so I've gone ambient.

 

[Glow]

In my veg, I'm stuck with temps in the mid 80's. The best I understand everything I've read, high end VPD/RH is the best I can do to combat those temps. My understanding of @Glow literature is RH over 55% negates the benefits of CO2 enrichment so I've gone ambient.

No, where did I say that?? As long as the stomata are open the plant absorbs CO2

 

[3 balls]

No, where did I say that?? As long as the stomata are open the plant absorbs CO2

I just re-read it, 55% or lower in flower but further down it does say 65% in veg.

 

[Glow]

I just re-read it, 55% or lower in flower but further down it does say 65% in veg.

No what I am saying there is to try to keep humidity lower in flower due to the risk of fungal pathogens. The main thing with CO2 is the plant will use it if the stomata are open. That creates quite a wide range re RH.