What PAR are you cooking under ??

  • Thread starter Growtime818
  • Start date
  • Tagged users None
Growtime818

Growtime818

18
3
Running the led 1750 gavitas

what Par are people running in flower ?

Have it set 950-1050 par mid flower (top of canopy) at 90% watt usage.

Ran the area at max with different strains previously.

running co2 at 1500-1600 ppm
what par are people running ?

Gelatto 33 day 32
 
Dirtbag

Dirtbag

Supporter
9,052
313
Nice looking room. With Co2 like that, if temps and humidity and feeding is right, you should be able to push 1400-1500 ppfd at the canopy. There are some excellent videos by Dr Bruce Bugby regarding ppfd values and the variables related to it. I'll see if I can find the more recent one I watched that was pretty good.
 
ImpulsiveGrower

ImpulsiveGrower

Supporter
1,206
263
In veg I push 1000 ppfd with co2 around 1000-1200ppm. Flower I’ll be going for higher like @Dirtbag is mentioning…
 
ComfortablyNumb

ComfortablyNumb

5,770
313
Nice looking room. With Co2 like that, if temps and humidity and feeding is right, you should be able to push 1400-1500 ppfd at the canopy. There are some excellent videos by Dr Bruce Bugby regarding ppfd values and the variables related to it. I'll see if I can find the more recent one I watched that was pretty good.
Doc Bruce and Ed Rosenthal are da Men!
 
Dirtbag

Dirtbag

Supporter
9,052
313
I'm actually just diving into this subject myself, it's been overlooked by me for a long time, but I'm gonna play around with enriching Co2 and high ppfd this grow. The potential for yield increase is alluring since I've downsized the grow space.
 
Dirtbag

Dirtbag

Supporter
9,052
313
I think one aspect that I overlooked that makes a lot of sense now is the drop in DLI when switching to 12/12. Explains why I used to get fert buildup in early flower if I vegged and flowered under 1kHPS. Stopped happening when I started ramping up light near flower.

Looking forward to using this info to now work up the light intensity greatly after transition to flower in addition to gas. Really curious to see what happens.
 
Growtime818

Growtime818

18
3
Thanj
I think one aspect that I overlooked that makes a lot of sense now is the drop in DLI when switching to 12/12. Explains why I used to get fert buildup in early flower if I vegged and flowered under 1kHPS. Stopped happening when I started ramping up light near flower.

Looking forward to using this info to now work up the light intensity greatly after transition to flower in addition to gas. Really curious to see what happens.
Thank you my man, I’m going to be tinkering with it. I’m a bit late as I’m day 34 but not that late. Will be cranking her up slowly this week.
 
jguit

jguit

Supporter
899
143
I think one aspect that I overlooked that makes a lot of sense now is the drop in DLI when switching to 12/12. Explains why I used to get fert buildup in early flower if I vegged and flowered under 1kHPS. Stopped happening when I started ramping up light near flower.

Looking forward to using this info to now work up the light intensity greatly after transition to flower in addition to gas. Really curious to see what happens.
I'm trying to digest this. Are you saying the drop in DLI at the transition from veg to flower causes a salt buildup because the plant is taking up less nutrients during this time?
 
ComfortablyNumb

ComfortablyNumb

5,770
313
I'm trying to digest this. Are you saying the drop in DLI at the transition from veg to flower causes a salt buildup because the plant is taking up less nutrients during this time?
That is exactly what he is saying. Because the plant has less light, it does not need as much of everything else.
When you watch Dr. Bruce, he tells you that the more light, the more of everything else you need. So when @Dirtbag changed to 12/12 he lost X amount of light but did not cut the nutes accordingly.

This is why you run veg at a lower light level so when you change to flower, you can up the light power to keep the plants needs stable.
 
Dirtbag

Dirtbag

Supporter
9,052
313
That is exactly what he is saying. Because the plant has less light, it does not need as much of everything else.
When you watch Dr. Bruce, he tells you that the more light, the more of everything else you need. So when @Dirtbag changed to 12/12 he lost X amount of light but did not cut the nutes accordingly.

This is why you run veg at a lower light level so when you change to flower, you can up the light power to keep the plants needs stable.
Bingpot. Thanks, couldn't have said it better.

I will elaborate to help people understand it because It confused me at first too. The way Bruce explains it, think of photons as marbles falling from the sky. The plants catch these marbes and use them along with nutrients and Co2 to produce energy for growth. The more marbles it catches, the more nutrients and co2 it needs, and vice versa.
If you think of the marbles falling at a constant rate it's obvious the plant will catch more marbles in 18hrs than it will in 12, which means it has less need for nutrients in a 24hr day if the light level stays the same.
By increasing the light intensity during flower to match, or at least come close to the number of photons collected during the veg cycle means the plant should continue using roughly the same concentration of nutrients if all other parameters stay the same.

Knowing the Daily Light Interval or DLI let's you know roughly how much food and carbon dioxide is required to balance the plants inputs for optimal growth. It's a more important variable to consider than I ever.. considered? Lol.
 
Last edited:
ComfortablyNumb

ComfortablyNumb

5,770
313
DLI is the number that tells you how much you need to feed, not the chart on the bottle.
 
ComfortablyNumb

ComfortablyNumb

5,770
313
1570 lux? That's 1570*.023 = 36.11par?
36.11*18hours = 649.98 DLI
Keep track of that number.
 

Similar threads

VinnieV
Replies
7
Views
849
VinnieV
VinnieV
kurupdid
Replies
5
Views
852
MIMedGrower
MIMedGrower
Urameshi
Replies
27
Views
2K
Urameshi
Urameshi
Top Bottom