DLI and PPFD Questions???

[Cerebral Goo]

For those of you that follow DLI what DLI and/or PPFD do you run per week or other time increment? Basically week 1, week 2(seedling) week 3, week 4(veg) etc...Obviously this would/could change depending on what the plants like. Am looking for ball park figures of the amount of light and when to bump up the PPFD. The charts that list 100-300 for seedling, 300-600 for veg, 600+ for flower seem to be a little vague.

I am around day 14 and wondering when to increase the PPFD and how much. Started the seedlings off at 150-175 and have slowly raised it every couple of days and at 230-250 now. I was leaving lights on 24/0 but looking to change to 20/4. Leaves are looking a little lighter green and a little droopy at certain times of the day.

Many thank you's in advance to everyone!!!

 

[terp182]

I'm no expert so pinch of salt, but I just use the Photone app and check the DLI for my schedule (20/4) at canopy height, and adjust the light to that level for them. I think DLI is a lot more relevant to autoflowers than PPFD since the schedules are significantly longer, but I could be wrong.

DLI of course stands for Daily Light Integral, so that's how much light your plants can absorb in 24 hours. And yes, seedlings to early veg need less light as they grow roots, then more as leaves are established. Either way, the DLI should guide you well. Good luck!

 

[Mañ'O'Green]

For those of you that follow DLI what DLI and/or PPFD do you run per week or other time increment? Basically week 1, week 2(seedling) week 3, week 4(veg) etc...Obviously this would/could change depending on what the plants like. Am looking for ball park figures of the amount of light and when to bump up the PPFD. The charts that list 100-300 for seedling, 300-600 for veg, 600+ for flower seem to be a little vague.

I am around day 14 and wondering when to increase the PPFD and how much. Started the seedlings off at 150-175 and have slowly raised it every couple of days and at 230-250 now. I was leaving lights on 24/0 but looking to change to 20/4. Leaves are looking a little lighter green and a little droopy at certain times of the day.

Many thank you's in advance to everyone!!!

Unless you cannot get to 42 DLI Minimum for Autos with your lights over 18 hours I would suggest 18/6. I run 50 DLI 18/6 on my plants after the first two weeks.

I'm no expert so pinch of salt, but I just use the Photone app and check the DLI for my schedule (20/4) at canopy height, and adjust the light to that level for them. I think DLI is a lot more relevant to autoflowers than PPFD since the schedules are significantly longer, but I could be wrong.

DLI of course stands for Daily Light Integral, so that's how much light your plants can absorb in 24 hours. And yes, seedlings to early veg need less light as they grow roots, then more as leaves are established. Either way, the DLI should guide you well. Good luck!

@terp182 DLI is a measure of the PPFD over time.

 

[Cerebral Goo]

Unless you cannot get to 42 DLI Minimum for Autos with your lights over 18 hours I would suggest 18/6. I run 50 DLI 18/6 on my plants after the first two weeks.


@terp182 DLI is a measure of the PPFD over time.

Wow! looks like I have a lot of catching up to do. So, you are at roughly 775 PPFD after two weeks? How much do you think I should bump up the PPFD and at what time frame as to not shock or over burden the plants? 50-75 PPFD per day? More PPFD than that and/or over a couple of days so they have time to acclimate to each increase?

I have a Photontek 600 W Pro which maxes out at 1400 umols in a Gorilla 4x4. So, I have plenty of light. However, being a noob and from most of what I have read, was hesitant about too much light at that early stage.

Thanks again so much for your time!!!

 

[Mañ'O'Green]

Wow! looks like I have a lot of catching up to do. So, you are at roughly 775 PPFD after two weeks? How much do you think I should bump up the PPFD and at what time frame as to not shock or over burden the plants? 50-75 PPFD per day? More PPFD than that and/or over a couple of days so they have time to acclimate to each increase?

I have a Photontek 600 W Pro which maxes out at 1400 umols in a Gorilla 4x4. So, I have plenty of light. However, being a noob and from most of what I have read, was hesitant about too much light at that early stage.

Thanks again so much for your time!!!

I don't have a formula I just turn it up over a few days. That is as high as I run autos. I run my photoperiod plants as high as 60 DLI 1200 PPFD 12/12.

I have Royal Blue pucks that I run in veg, Far Red Initiator pucks for the stretch, UVA for terps in bloom and UVB for THC in late flower.

 

[Cerebral Goo]

I don't have a formula I just turn it up over a few days. That is as high as I run autos. I run my photoperiod plants as high as 60 DLI 1200 PPFD 12/12.

I have Royal Blue pucks that I run in veg, Far Red Initiator pucks for the stretch, UVA for terps in bloom and UVB for THC in late flower.

Thanks again for your input! Will definitely check out the puck lights and have looked at UVB as well. Will crank up the lights and see what happens!!!

 

[Mañ'O'Green]

These are what I am using. Dont forget the UVA for better terp profile.

 

[Modernviking]

I'm new as well but this is what hlg suggested I use when I emailed them.
Hlg ppfd calculator

 

[CannabisMingus]

I run 50 DLI 18/6 on my plants after the first two weeks.

@Mañ'O'Green - Just to clarify, you run 50 DLI from veg to chop? Just got a new light and am working out DLI ranges. TIA!

 

[Cerebral Goo]

I'm new as well but this is what hlg suggested I use when I emailed them.
Hlg ppfd calculator

Thanks for the reply! I was trying to fish out some specifics of what people are actually doing. For what its worth, as you can see by Man O Greens comment, it seems like after the first two weeks, you can crank up the light. If you think about outdoors, the sun doesn't cut down the ppfd,,,Where the point of diminishing returns is the question?