PAR CO2 - Guide & Questions - MAX Yield

Muzzle2

Well-Known Member
What's up yawl! Just trying to figure out a few things here before I commit to this project of mine.

My setup is pretty legit, I've got CO2, Dehu, LEDs, and a bunch of air circulation. Super clean, detailed, and tidy environment. I've got 3 lights and I'm trying to see how I can maximize production per light. I've been thinking that if I understand the below questions I'll be able to potentially control how much I can produce.

Here are a couple of questions I have and wanted to see if I could get some direct insight.

Basic questions is, LEDs go from 50% - 115%, I'm assuming that with the increase of percentage, and the distancing of the LEDs from the top controls the PPFD produced. So in short I would have to run tests like, at 60% and 18in from top what's the PPFD, etc.. Is this correct?

On a 12/12 schedule with Gavita 1700e LEDs what should my PAR schedule look like? I've read 600-900 PPFD is optimal, but I have also read that 1500 PPFD with supplemented CO2 can maximize the growth.

How would I measure how much CO2 to supplement to the plant, based on the par level? I want to make sure I'm able to provide the perfect amount of CO2, to PAR ratio. Not sure what the scientific terms and approach to this would be.

On a 18/6 schedule, I've read that 400 - 600 PPFD is optimal, but I've also read for top threshold for optimal grow is 1000 PPFD. What's your guys experience like?

I've also read on this forum that lowering the PAR in bloom increases trichome production, but I wasn't able to find out in what week of bloom would this lowering have to happen?

I have complete control over the environment and I also want to understand how temperature plays a role in this, do I have to adjust the temperature based on the PPFD or CO2 I want to pump in the room?

I hope these are too many questions that require complex answers, but I am trying to get an idea before I stick anything in there and start messing around.

Appreciate ANY and ALL input!
 

kingromano

Well-Known Member
What's up yawl! Just trying to figure out a few things here before I commit to this project of mine.

My setup is pretty legit, I've got CO2, Dehu, LEDs, and a bunch of air circulation. Super clean, detailed, and tidy environment. I've got 3 lights and I'm trying to see how I can maximize production per light. I've been thinking that if I understand the below questions I'll be able to potentially control how much I can produce.

Here are a couple of questions I have and wanted to see if I could get some direct insight.

Basic questions is, LEDs go from 50% - 115%, I'm assuming that with the increase of percentage, and the distancing of the LEDs from the top controls the PPFD produced. So in short I would have to run tests like, at 60% and 18in from top what's the PPFD, etc.. Is this correct?

On a 12/12 schedule with Gavita 1700e LEDs what should my PAR schedule look like? I've read 600-900 PPFD is optimal, but I have also read that 1500 PPFD with supplemented CO2 can maximize the growth.

How would I measure how much CO2 to supplement to the plant, based on the par level? I want to make sure I'm able to provide the perfect amount of CO2, to PAR ratio. Not sure what the scientific terms and approach to this would be.
-->stay between 800 and 1500ppm of co2

On a 18/6 schedule, I've read that 400 - 600 PPFD is optimal, but I've also read for top threshold for optimal grow is 1000 PPFD. What's your guys experience like?
-->it's high for veg, you can do it but you need to acclimate the plants to this intensity
for light intensity in veg, less is better
i wouldnt give 1000micromoles/s during 18 hours though


I've also read on this forum that lowering the PAR in bloom increases trichome production, but I wasn't able to find out in what week of bloom would this lowering have to happen?
-->no, to maximise yield and trichomes production you need to increase light intensity
you want to follow an increasing curve for light intensity during bloom, 1500 micromoles.s is for the last part of flowering


I have complete control over the environment and I also want to understand how temperature plays a role in this, do I have to adjust the temperature based on the PPFD or CO2 I want to pump in the room?
-->try to keep 28-30 degree C leaves temperature, and 22degree at the root zone. if your system is well designed you will be able to.

I hope these are too many questions that require complex answers, but I am trying to get an idea before I stick anything in there and start messing around.

Appreciate ANY and ALL input!
 

Renfro

Well-Known Member
I was always under the impression that the temp should be 75-78 degrees f

this was great input thank you
Infrared light warms surfaces it hits. Under HPS that has a lot of infrared you want cooler temps like around 79F for the high. Under LED we don't have that abundance of IR light to warm up the leaves so to achieve proper leaf surface temperatures under LED we need warmer air temps, in the mid 80's.
 

kingromano

Well-Known Member
true
that's why i prefer hps over leds
allow me to get warm temps at canopy and keep root zone cool
i set the AC's on 75F to get 80-85 leaves temperature

a infrared thermoemeter is very useful in this case

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Muzzle2

Well-Known Member
Okay, that makes more sense now. I should be able to pull those leave temperatures. Anyone else have any clue on how LED percentage output contributes to the PAR? For example, is it better to go lower output, closer distance, or higher output further distance.
 

Muzzle2

Well-Known Member
I've also read on this forum that lowering the PAR in bloom increases trichome production, but I wasn't able to find out in what week of bloom would this lowering have to happen?
-->no, to maximise yield and trichomes production you need to increase light intensity
you want to follow an increasing curve for light intensity during bloom, 1500 micromoles.s is for the last part of flowering
So from week 1 of flower, I'd start at like 800 micromoles.s and then by week 8 I should be at 1500? Also, what would my co2 be during this entire time? 800 - 1500?
 

Muzzle2

Well-Known Member
I just wanted to revive this conversation. I feel like I've been going mainly off of VPD and and haven't been paying attention to PPFD. It's been a while, but I want to try this on my next run.
 
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