Should nutrients (ppm) be increased with Co2 enrichement?

[Helmut79]

I know that Co2 works better with higher temps than usual. Higher temp itself increases the rate of watering needed.

Now I have heard that PPM's should be slightly lowered if dealing with exessive heat, because you will need to water more often and plant will therefore consume slightly more nutrients too.

Sounds kind of like a contradiction to me.

How does it apply to Co2 enrichement?

Is it a common sense to increase PPM's of nutrients when enriching with Co2 or not?

 

[chemphlegm]

if you cant control the temps and humidity in your space perfectly stay with air exchange until you can.
your space, conditions, plant experience, genetics will dictate your nutrient use. I would say change nothing so you can
detect the difference first. Plants will consume (hydro) available nutrients as needed. They will not starve if bottle directions are followed with or without c02 augmentation.
I do not feed any more or less since I sealed my room and use c02 years ago. My plants show a fuller expression and a more complete finish, smellier, thicker, on time harvests since I sparked my c02 generator inside the room

 

[Helmut79]

So you're basically saying less is more.

I get it. Overabundance is worse than a slight deficit.

The difference I'm getting is slightly too pale leaf color closest to light, hence the feeling that maybe I should increase nutrient uptake.

Got light movers and stuff, so shouldn't bee to close, although it's 1150W.

I'm kindly asking if it's reasonable to increase PPM if CO2 is introduced. What is your first sentence about?

 

[Helmut79]

I found an interesting post at grasscity:

Like 5Jperday said above... its pretty much pointless to run Co2 unless you have HID lights. If your light intensity is too low, then your plants wont take in more then 400ppm of Co2 anyway, which is already in the air... so adding Co2 would be pointless.

Now if your environment and light intensity is right, then Co2 can and will give you an easy 20-40% increase in yield. And like someone else mentioned above... raising the temperatures will allow your plants to breath in even more Co2, increasing growth even more. Once you get to about 90 degrees is when the plant starts to shut down a little. If your over 85 degrees then your buds will start to loosen up some, so 80-83 degrees is about as high as I will take them. And that temperature isnt room temperature, but its the temps at the canopy.

Co2 increases growth... if growth is increased, then the amount of nutrients they eat also increases... as well as water consumption. I've had the PPM of my nutrients above 2,000 ppm with great results. The key is knowing how much it too much. I increase nute ppm until I see just the very tip of the leaves starting to burn. Then I back off some, and thats where I keep the PPM of nute. All strains are different too. My White Widow is nute sensitive, and will fry at 2,000ppm. My LA Woman is a heavy eater that I've actually never been able to burn.

Also someone commented on yellow leaves above. Magnesium is not the problem. Nitrogen is. Usually when you switch to flowering, you also switch your nutrients to flowering nutrients. Flowering nutrients have a much lower Nitrogen content then veg nutrients. People also say that plants naturally start to yellow towards the end of flowering... this is true in nature, but not in indoor growing. Check out some of my pics on my thread below.... I've kept my plants very dark green through the entire cycle, even when its time to chop my plants down, they were still dark lushy green. I only did that twice, just to see if I can do it, because the green that you see is Chlorophyll. One of the keys to growing connoisseur weed, is to get all of that chlorophyll out of your plants before harvest. Chlorophyll gives weed a very nasty taste and will add to its harshness and can give a grassy smell to your weed.

 

[chemphlegm]

I'm kindly asking if it's reasonable to increase PPM if CO2 is introduced. What is your first sentence about?

you mentioned excessive temps.

plants grow to their weakest resource. c02 wont improve a thing unless lack of c02 is the issue.
I've found growers adding c02 to their rooms often end up with more issues than before the addition.
If there's an issue....a c02 generator will likely make it worse, and c02 tanks will waste cash.

I dont water anymore now than when I didnt use c02 btw. My air conditioning and dehumidifying costs went up, as controls keep the same conditions constant. The only resource I didnt master here was air exchange so I added c02 instead, and found it to be the last thing I needed for a perfect finish. I use less fertilizer now than ever before.

It is not reasonable to increase nutrient PPM's for the addition of c02

this quote puzzles me a little.....

the room controls should keep canopy temps the same as corner temps for best results.
40% increase because of c02? you'll likely not see this



that post is confusing to me.
"People also say that plants naturally start to yellow towards the end of flowering... this is true in nature, but not in indoor growing."

but then he is smart here, when he realizes .... plants actually do yellow when fed correctly, and taste better for it, and thats why he stopped feeding so heavy at the finish--below....

says this "I've kept my plants very dark green through the entire cycle, even when its time to chop my plants down, they were still dark lushy green. I only did that twice, just to see if I can do it, because the green that you see is Chlorophyll. One of the keys to growing connoisseur weed, is to get all of that chlorophyll out of your plants before harvest. Chlorophyll gives weed a very nasty taste and will add to its harshness and can give a grassy smell to your weed."

 

[Dr. Who]

The use of Co2 increases up-take. There are factors that work as limiters.

Light intensity, Temps and RH are the big 3. When gassing, it's prudent to be aware of following the VPD charts. (Vapor Pressure Deficit)

I liked about 90 and an RH of low 80's when I gassed.

FYI, gassing at over 1300 ppm is basically useless. Not many can supply the needed light intensity to make that work right, and over 1500 is simply wasting gas/money....

 

[Daveindiego]

The use of Co2 increases up-take. There are factors that work as limiters.

Light intensity, Temps and RH are the big 3. When gassing, it's prudent to be aware of following the VPD charts. (Vapor Pressure Deficit)

I liked about 90 and an RH of low 80's when I gassed.

FYI, gassing at over 1300 ppm is basically useless. Not many can supply the needed light intensity to make that work right, and over 1500 is simply wasting gas/money....

Thanks.
: adjusts co2 monitor back down to 1400 :

 

[Dr. Who]

Thanks.
: adjusts co2 monitor back down to 1400 :

2 cents? I liked 1200 as my limit.....But please try/do what you like!

For tents (4x4 and less) and 600 w lights - 1000 ppm.....
Knowing and figuring in umals of light is an advantage for figuring your light delivery.

 

[Daveindiego]

2 cents? I liked 1200 as my limit.....But please try/do what you like!

For tents (4x4 and less) and 600 w lights - 1000 ppm.....
Knowing and figuring in umals of light is an advantage for figuring your light delivery.

Thanks again.

: readjusts monitor :

 

[Helmut79]

I use less fertilizer now than ever before.

It is not reasonable to increase nutrient PPM's for the addition of c02

 

[Helmut79]

FYI, gassing at over 1300 ppm is basically useless. Not many can supply the needed light intensity to make that work right, and over 1500 is simply wasting gas/money....

Spurr says it should not be over 1200. He seems to know what he's talking about:

The facts about CO2 ppm: don't use 1,500!
High,

I haven't posted much lately, but I thought this topic was important enough to write a thread. I have written about this topic quite a lot in the past, but I have never made a thread just for this topic.

My goal: to try and kill the myth that 1,500 ppm CO2 is ideal. I want to get it known in the cannabis world, that it's important to not use > ~1,100-1,200 ppm CO2.

In short, the claim that 1,500 ppm CO2 is ideal for cannabis is total hogwash. I challenged anyone a while ago to find a single scientific study showing 1,500 ppm is ideal for C3 flowering plants, or even just to find the reasons why it's claimed 1,500 ppm is ideal in the cannabis world. I assume the myth (yet another!) came from the liked of Ed Rosenthall or George Cervantes or Mel Frank, etc.

If there is interest in the 'whys' I can explain why it's important to not use > 1,200 ppm, ideally we would use ~1,000-1,100 ppm. The effects from "super-optimal" CO2 concentrations range from reduced rate of photosynthesis, to reduced yield, reduced root growth, reduced stomatal openness, increased photorespiration, etc. In other words, nothing good.

The reason why we should ideally use ~1,000 ppm, is for most C3 species (and C4 I think), CO2 "saturation" occurs at ~1,000-1,100 ppm. That means more than ~1,100 ppm (up to 1,200 ppm) isn't going to help the plants, it's only going to waste CO2 and hinder plants if CO2 is about > 1,200 ppm.

The reason why we should ideally use < 1,200 ppm CO2 is the effect high (super-optimal) CO2 has on "Rubisco activase", the substance that turns inactive "Rubisco" into active Rubsico. At CO2 > ~1,200 (and temp > ~89'F) Rubsico activase is inhibited, which in turn inhibits conversion of inactive Rubisco into active Rubisco. And active Rubisco is needed for high rate of photosynthesis, which in turn leads to high growth rates and high yield, etc.

So, to sum up: It's important to keep CO2 below ~1,200, and to be safe and most efficient, keep CO2 at ~1,000 ppm. Night time CO2 should be < ~500 ppm, unless one is trying to reduce dark respiration and stretch, then upwards of 750 ppm can be used for short periods (otherwise leaf chlorosis can set in)

I can fully cite all those claims, if anyone wants to read the academic lit.

 

[Dr. Who]

I can fully cite all those claims, if anyone wants to read the academic lit.

I would like to read that please. Not disagreeing at all, just want to read the paper.

You can PM that if you like.

To even make 1300 ppm usable by the plant... You would need to deliver 48,240 lux (I use lux as it's easier to understand then mol). A 1k HPS does not deliver that amount of light energy.....I listed 1300 ppm as a high end limit, by lighting limitations.
Your information is quite interesting. Even though I don't gas anymore. At some point you can discover that when growing for potentials, you don't need to... While it does speed up a run. It's not worth the cost to return to make it a viable choice for Me!

Thank you Helmut

 

[Eph3m3raL]

Spurr says it should not be over 1200. He seems to know what he's talking about:

The facts about CO2 ppm: don't use 1,500!
High,

I haven't posted much lately, but I thought this topic was important enough to write a thread. I have written about this topic quite a lot in the past, but I have never made a thread just for this topic.

My goal: to try and kill the myth that 1,500 ppm CO2 is ideal. I want to get it known in the cannabis world, that it's important to not use > ~1,100-1,200 ppm CO2.

In short, the claim that 1,500 ppm CO2 is ideal for cannabis is total hogwash. I challenged anyone a while ago to find a single scientific study showing 1,500 ppm is ideal for C3 flowering plants, or even just to find the reasons why it's claimed 1,500 ppm is ideal in the cannabis world. I assume the myth (yet another!) came from the liked of Ed Rosenthall or George Cervantes or Mel Frank, etc.

If there is interest in the 'whys' I can explain why it's important to not use > 1,200 ppm, ideally we would use ~1,000-1,100 ppm. The effects from "super-optimal" CO2 concentrations range from reduced rate of photosynthesis, to reduced yield, reduced root growth, reduced stomatal openness, increased photorespiration, etc. In other words, nothing good.

The reason why we should ideally use ~1,000 ppm, is for most C3 species (and C4 I think), CO2 "saturation" occurs at ~1,000-1,100 ppm. That means more than ~1,100 ppm (up to 1,200 ppm) isn't going to help the plants, it's only going to waste CO2 and hinder plants if CO2 is about > 1,200 ppm.

The reason why we should ideally use < 1,200 ppm CO2 is the effect high (super-optimal) CO2 has on "Rubisco activase", the substance that turns inactive "Rubisco" into active Rubsico. At CO2 > ~1,200 (and temp > ~89'F) Rubsico activase is inhibited, which in turn inhibits conversion of inactive Rubisco into active Rubisco. And active Rubisco is needed for high rate of photosynthesis, which in turn leads to high growth rates and high yield, etc.

So, to sum up: It's important to keep CO2 below ~1,200, and to be safe and most efficient, keep CO2 at ~1,000 ppm. Night time CO2 should be < ~500 ppm, unless one is trying to reduce dark respiration and stretch, then upwards of 750 ppm can be used for short periods (otherwise leaf chlorosis can set in)

I can fully cite all those claims, if anyone wants to read the academic lit.

Can you please link the articles?

 

[Helmut79]

You can find it by googling the title: The facts about CO2 ppm: don't use 1,500!

 

[Americanadian420]

So you're basically saying less is more.

I get it. Overabundance is worse than a slight deficit.

The difference I'm getting is slightly too pale leaf color closest to light, hence the feeling that maybe I should increase nutrient uptake.

Got light movers and stuff, so shouldn't bee to close, although it's 1150W.

I'm kindly asking if it's reasonable to increase PPM if CO2 is introduced. What is your first sentence about?

Hey did you ever figure this out??? On my second grow exactly the same but this time added c02 and only 45 days into my 70 day strain the leaves in the middle where the light are are literally turning yellow and it’s been for 2 weeks I been feeding but nothing getting better seems slowly getting hungrier. I just gave them twice the ppm I usually do to see if they finally start greening up. And I say exactly the same because it’s only the parts under the light all the outer branches seem green and healthy but still yellowing a BIT On the bottom but nothing like the center. After nothing changing I just realized it HAS to be the added c02 so I’m gonna up my feed by 500ppm hopefully should help. Cuz they were getting very low feedings

 

[kmog33]

Hey did you ever figure this out??? On my second grow exactly the same but this time added c02 and only 45 days into my 70 day strain the leaves in the middle where the light are are literally turning yellow and it’s been for 2 weeks I been feeding but nothing getting better seems slowly getting hungrier. I just gave them twice the ppm I usually do to see if they finally start greening up. And I say exactly the same because it’s only the parts under the light all the outer branches seem green and healthy but still yellowing a BIT On the bottom but nothing like the center. After nothing changing I just realized it HAS to be the added c02 so I’m gonna up my feed by 500ppm hopefully should help. Cuz they were getting very low feedings

This thread is three years old you may not get a response

 

[Laughinggrass420]

The use of Co2 increases up-take. There are factors that work as limiters.

Light intensity, Temps and RH are the big 3. When gassing, it's prudent to be aware of following the VPD charts. (Vapor Pressure Deficit)

I liked about 90 and an RH of low 80's when I gassed.

FYI, gassing at over 1300 ppm is basically useless. Not many can supply the needed light intensity to make that work right, and over 1500 is simply wasting gas/money....

Dealing with a very undialed room right now and I inject ( neighbors ) my temps are at first glance great 81-84 rh 55-65 (My leaf surface temp is about 4 degrees cooler than my canopy so I believe that’s why I run a little drier than yourself)

high intensity led

maybe you can offer some insight.

feeding at 1.6 ec flora flex
.75 ml silica .2 ec calimagic and the rest base.
watering to significant run off 2 x a day

 

[Lordhooha]

Dealing with a very undialed room right now and I inject ( neighbors ) my temps are at first glance great 81-84 rh 55-65 (My leaf surface temp is about 4 degrees cooler than my canopy so I believe that’s why I run a little drier than yourself)

high intensity led

maybe you can offer some insight.

feeding at 1.6 ec flora flex
.75 ml silica .2 ec calimagic and the rest base.
watering to significant run off 2 x a day

Adding co2 into a room that’s not dialed in is asking for trouble. What light are you using because the node spacing is not as tight as I’d want it. so either it’s not really that much light or it’s too high.

 

[Laughinggrass420]

Adding co2 into a room that’s not dialed in is asking for trouble. What light are you using because the node spacing is not as tight as I’d want it. so either it’s not really that much light or it’s too high.

I think the room is reasonably dialed in regards to vpd. Think. Spider 2i.
1 foot from canopy’s at 60 percent. No par meter but I imagine I’m at about 1000 mols.
Just saying that seems a big high

 

[Laughinggrass420]

Adding co2 into a room that’s not dialed in is asking for trouble. What light are you using because the node spacing is not as tight as I’d want it. so either it’s not really that much light or it’s too high.

Feel like I need to kick nutes up and I hate myself for even saying that but my approach is to up nitro back off p and k a bit keep light the same. Tough run