Decreasing Temps & CO2 From Veg To Flower?

[cannaguru]

Was checking out Current Culture's website and their recommended graph which is pretty cool.

General Recommendations - Current Culture H2O

I was pretty shocked to see that they are suggesting a decrease in CO2 PPM progressively from week 2 onward. This is contrary to everything I have done in the past and things I have read elsewhere. So many of the grows I know don't even use CO2 augmentation in veg that it's really blowing my mind.

Now I have been doing this a long time, studied plenty of scientific studies which do indeed show that CO2 usage is proportional to temperature. In fact if you run your room in the 70's having anything above 1000ppm is useless. But, run your room in the upper 80's or even low 90's and high PPM's are essentially a requirement.

CO2 Science

Now CCH2O also is keeping those temps down low and getting them lower as time goes on. Again, this is opposite what I have done in the past and learned from others. Seeing the science of CO2 and it's effects at higher temps, I am questioning the wisdom of growing in the mid 70's during critical flower production time especially when you are chilling your water.

Can anyone give any feedback on having higher PPM's and temps in Veg and lowering it in flowering???

 

[LEDBud]

Quote cannaguru :
Now I have been doing this a long time, studied plenty of scientific studies which do indeed show that CO2 usage is proportional to temperature. In fact if you run your room in the 70's having anything above 1000ppm is useless. But, run your room in the upper 80's or even low 90's and high PPM's are essentially a requirement.
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Sorry I can't provide you with any confirmation as I only use a crude propane burner for Co2 generation without a meter, I am interested in the temperature findings you have discovered on that site.

I myself find the findings counter intuitive. As I understand it the plants root zone does not thrive in the elevated high 80's temperatures , nor do they tell you to preheat your water or nutrient solution to the high 80's for best results.
I have been told and read that your water / nutrient solution should be kept between 67 and 72*f and seedling trays no hotter then 75*f.

Yet the plants are suggested to thrive in the high 80's temperatures with added Co2 .. sounds fishy but I have not tested it.

What temperature do you keep your grow room at and what benefit are you seeing from your Co2 enrichment ?


Perhaps some other members who use Co2 will chime in with their experiences with room temperature to compare

 

[cannaguru]

It's not the water temps they are talking about being in the 80's. As you can see from the chart they are saying keep the water 68-64deg which it totally correct in my experience. 67deg till the end and 64 last few weeks to bring out color. I am cool with that.

What I find odd is the fact they are saying to use more CO2 in the beginning (week2 - 1400ppm) than in the middle of flowering!!! (700ppm) .. in the past I never added CO2 in veg and my ppm in flower was 1400-1500. Also... I flower with temps higher than 72deg air temp...

As stated in the 2nd graph and from my experience... the higher the temp.. the more benefit from high CO2. Everything I have read says running flower at 88deg and high CO2 will outperform 72deg and 700ppm.

 

[LEDBud]

Your finding suggest the plants prefer their containers warm/hot @ 88 + degrees when using Co2 , as the buckets / containers would match the rooms temperature threw heat soak.
I deduce the nutrient solution or water would be the rooms temperature 88* or higher in some hours , after being applied.

My conclusion is it would in effect be heating the water / root zone to the same room temperature.

Curious what your take on it is , if my premise that the container temperature then water is being directly effected by the rooms temperature.


I may be missing a important part of the watering temperature reaction, could be a cooling effect is taking place by the water threw absorption or evaporation , causing the containers to be air conditioned , much like a swap cooler does.

 

[cannaguru]

No.... CCH2O systems are meant and ONLY run with an inline water chiller. The root-zone temps (See water temps in the bottom line of the first chart) say to keep the root zone cool all the time (never more than 68deg) ... this is true and something I have always done. The reason is because dissolved oxygen peaks at that temp and that is how DWC works.

So the issues that I find most odd are they they suggest lower and lower air temps (higher in veg) (lower in flowering) which also means decreasing CO2 levels in flower. The air temps they suggest are much lower than what I have used in the past and I have always used higher temps in flower (to "ripen") and also because it causes faster photosynthesis (see 2nd graph) ... this Air temp and CO2 is what I am having a hard time digesting.

 

[LEDBud]

O.k ,
so according to the info the high 60's low 70's is the sweet spot for the plants Co2 absorption , meaning it can readily absorb the co2 in the concentrations mentioned , as that is the amount the plant can digest at that moment with maximum effect.

On the opposite side , in high heat conditions the plants need a environment with much higher Co2 ppm to accomplish the same absorption rate.

The heat must slow the Co2 absorptions processes down considerably , which indicates to me the Plants like cool room temperatures , just like the roots do.


It would be interesting to test , and compare results of the end product , booth harvest size and the trichomes production.
I have *thought* the warmer temperatures could help to increase the trichomes count. Which may just be wishful thinking on my part.


You Should really test it out , Since you normally use more Co2 at warmer temperatures you should notice a difference if there is one.

 

[cannaguru]

I spoke with CCH2O about this. Admittedly, they claim this is the recipe for the highest yield of flower not necessarily of weight or oil. They said it was created and tweaked about 3 years ago BEFORE everyone started doing things with their trim. So in response they admit the higher temps and CO2 levels will increase overall photosynthesis and very likely overall plant size BUT are still holding fast to the belief that this recipe will provide greater flower yield and less trimming.

Sounds like an experiment to me!

 

[wilson2]

I spoke with CCH2O about this. Admittedly, they claim this is the recipe for the highest yield of flower not necessarily of weight or oil. They said it was created and tweaked about 3 years ago BEFORE everyone started doing things with their trim. So in response they admit the higher temps and CO2 levels will increase overall photosynthesis and very likely overall plant size BUT are still holding fast to the belief that this recipe will provide greater flower yield and less trimming.

Sounds like an experiment to me!

so did you test it ? from what I have read the high co2 during veg was to increase the size of the plant for the limited veg time. I have read mixed results for yield increases during flower

 

[Chris Scorpio]

This thread is 4+ years old

Op hasn't been around since then