Is The Highest PPFD The Best?

[ViparSpectra]

We care about the PPFD while choosing a light for the grow, but is it " the highest PPFD, the best"? There has no photon density limits?

 

[Keffka]

What a loaded question lol.. I mean yeah PPFD is important but there’s so many factors.. What’s your goal? Do you have shareholders? How long are you running your lights? What’s your red ratio? What kind of light spread do you need? Is efficiency a concern?

Just like with growing the plant itself, there’s a balance we want to strike. Throwing 1200 PPFD at a plant is cool and all but is your light and environment really built for those levels? Are you using CO2? Red ratio will impact your flowers photo bleaching. It’s super difficult to pick just one factor and call it most important.

However if you’re forcing me into a single answer I would say your DLI trumps all. Quantity over quality. As long as your plant is getting the proper amount of light over a given time frame you can tinker with the other areas for improved results

 

[bluter]

However if you’re forcing me into a single answer I would say your DLI trumps all. Quantity over quality. As long as your plant is getting the proper amount of light over a given time frame you can tinker with the other areas for improved results

ppfd is central to DLI lol.

DLI is just a way of measuring environment. if you create a decent grow environment you are growing within it anyway. i don't worry about either. its really only newer growers getting rolled in to that stuff.

 

[Keffka]

ppfd is central to DLI lol.

DLI is just a way of measuring environment. if you create a decent grow environment you are growing within it anyway. i don't worry about either. its really only newer growers getting rolled in to that stuff.

Right that’s what I’m saying.. You can’t just ask “what’s the best”.. It’s all interconnected.. PPFD is necessary but it doesn’t mean anything if it’s only hitting your plants 6 hours a day. I chose DLI since it encompasses both PPFD and time. I view this question the same way as “what medium is best for growing?” Holy moly that’s a loaded question

 

[Keffka]

But yes I agree.. PPFD and DLI and all that are a lot of times gimmicky sales terms in relation to the greater grow. They don’t mean much if you don’t know how to water or feed your plants lol


I am being extremely rough here.. obviously all of these things are “important” but they’re also irrelevant if you don’t have the basics down

 

[ViparSpectra]

What a loaded question lol.. I mean yeah PPFD is important but there’s so many factors.. What’s your goal? Do you have shareholders? How long are you running your lights? What’s your red ratio? What kind of light spread do you need? Is efficiency a concern?

Just like with growing the plant itself, there’s a balance we want to strike. Throwing 1200 PPFD at a plant is cool and all but is your light and environment really built for those levels? Are you using CO2? Red ratio will impact your flowers photo bleaching. It’s super difficult to pick just one factor and call it most important.

However if you’re forcing me into a single answer I would say your DLI trumps all. Quantity over quality. As long as your plant is getting the proper amount of light over a given time frame you can tinker with the other areas for improved results

Thank you very much for your positive reply. Yes, we do not only consider one factor when planting, we need to consider many aspects.

 

[ViparSpectra]

ppfd is central to DLI lol.

DLI is just a way of measuring environment. if you create a decent grow environment you are growing within it anyway. i don't worry about either. its really only newer growers getting rolled in to that stuff.

Thanks for sharing your opinion!

 

[Odjob]

I use DLI outdoors. It pretty well covers 80% of how well things do in a season. Only thing if any indoors is to see if I need to replace bulbs. Watching the sun has given me lots of "would you look at that" events.

 

[Keffka]

I use DLI outdoors. It pretty well covers 80% of how well things do in a season. Only thing if any indoors is to see if I need to replace bulbs. Watching the sun has given me lots of "would you look at that" events.

Lol “would you look at that” gets me every time, damn internet. If I remember correctly, DLI started in outdoor greenhouses. They have to use it to account for diffuse light days, low light seasons, etc. basically it’s relative to the sun. They need to know when they’ve got to turn on which lights for how long to offset whatever the sun is doing or whatever season they’re in.

I ignored DLI for a while because it had been implied to me that DLI was really just an outdoor/greenhouse concern since inside growers can control the exact seconds a light hits a plant. As I thought more about these things for myself I realized it has just as much application indoors, if you’re growing photosynthetic plants indoors lol.

If a plant can handle unlimited PPFD then technically you could give it only 6 hours of light as long as you were blasting it with thousands of PPFD at once. The question I believe becomes a matter of whether it’s more economical to hit them hard and fast or more mellow over time.

I’m still learning about the nuances of lighting.. This is one of those subjects they don’t really teach unless you’re specializing in something. Which I find odd being that light is so crucial to our life.

 

[ViparSpectra]

Lol “would you look at that” gets me every time, damn internet. If I remember correctly, DLI started in outdoor greenhouses. They have to use it to account for diffuse light days, low light seasons, etc. basically it’s relative to the sun. They need to know when they’ve got to turn on which lights for how long to offset whatever the sun is doing or whatever season they’re in.

I ignored DLI for a while because it had been implied to me that DLI was really just an outdoor/greenhouse concern since inside growers can control the exact seconds a light hits a plant. As I thought more about these things for myself I realized it has just as much application indoors, if you’re growing photosynthetic plants indoors lol.

If a plant can handle unlimited PPFD then technically you could give it only 6 hours of light as long as you were blasting it with thousands of PPFD at once. The question I believe becomes a matter of whether it’s more economical to hit them hard and fast or more mellow over time.

I’m still learning about the nuances of lighting.. This is one of those subjects they don’t really teach unless you’re specializing in something. Which I find odd being that light is so crucial to our life.

Thanks for your sharing! DLI is important in growing. It measures how many photosynthetic active photons reach a specific area of the plant in a day's time. Always learning!

 

[Icemud]

A red 5mW laser has incredible PPFD in a single 2mm x 2mm area... but wouldn't be good at growing a plant worth 2 cents...

Therefore the answer is no... Too many factors play into it... High PPFD but poor canopy coverage.. not good... High PPFD but the wrong spectrum, not good, High PPFD but no CO2 supplements..wasted money/energy... and the list goes on and on.

 

[ViparSpectra]

A red 5mW laser has incredible PPFD in a single 2mm x 2mm area... but wouldn't be good at growing a plant worth 2 cents...

Therefore the answer is no... Too many factors play into it... High PPFD but poor canopy coverage.. not good... High PPFD but the wrong spectrum, not good, High PPFD but no CO2 supplements..wasted money/energy... and the list goes on and on.

Thanks for sharing your opinions. We do need to refer to many factors when growing.

 

[Delps8]

If a plant can handle unlimited PPFD then technically you could give it only 6 hours of light as long as you were blasting it with thousands of PPFD at once. The question I believe becomes a matter of whether it’s more economical to hit them hard and fast or more mellow over time.

Bugbee has said that, with CO2, they've run their plants at over 2000µmols. That's using C02, I'm sure, and in controlled conditions. What is most interesting to me is his attitude, about light as well as other things. He's very matter of fact about it.

That's fine in a lab and with CO2 but where does it leave the personal grower? Based on all of the research I've read and my limited experience (5 grows) — turn it up and leave it on. Like numerous researchers have demonstrated, plant yield, plant quality, crop yield, and crop quality increase as light levels increase. It's not quite linear but it's very close.

I aim for the cannabis light saturation point of 800-1000µmols, strain dependent, no CO2. I've run as high as 1200 and ended up with foxtails and, in a more recent grow (Gorilla Glue), did well as long as PPFD was < 950µmols. At that level, one of the colas bent - these were big colas, about 2" wide at the time and it bent at about a 45° angle.

Another grow was at 63 DLI for about a week and then 57± for the next month while my most recent grow was 60± from day 40 to day 110. All of them had a tremendous amount of growth and yields of 17 to 20 ounces, despite thrips infestations.

Light's the driver - more light, more food, more buds.

 

[ViparSpectra]

Bugbee has said that, with CO2, they've run their plants at over 2000µmols. That's using C02, I'm sure, and in controlled conditions. What is most interesting to me is his attitude, about light as well as other things. He's very matter of fact about it.

That's fine in a lab and with CO2 but where does it leave the personal grower? Based on all of the research I've read and my limited experience (5 grows) — turn it up and leave it on. Like numerous researchers have demonstrated, plant yield, plant quality, crop yield, and crop quality increase as light levels increase. It's not quite linear but it's very close.

I aim for the cannabis light saturation point of 800-1000µmols, strain dependent, no CO2. I've run as high as 1200 and ended up with foxtails and, in a more recent grow (Gorilla Glue), did well as long as PPFD was < 950µmols. At that level, one of the colas bent - these were big colas, about 2" wide at the time and it bent at about a 45° angle.

Another grow was at 63 DLI for about a week and then 57± for the next month while my most recent grow was 60± from day 40 to day 110. All of them had a tremendous amount of growth and yields of 17 to 20 ounces, despite thrips infestations.

Light's the driver - more light, more food, more buds.

Keeping CO2 levels around 1200-1500 PPM is ideal, but with higher CO2 levels in the environment, you'll want to keep your temperatures higher.

 

[Keffka]

Bugbee has said that, with CO2, they've run their plants at over 2000µmols. That's using C02, I'm sure, and in controlled conditions. What is most interesting to me is his attitude, about light as well as other things. He's very matter of fact about it.

That's fine in a lab and with CO2 but where does it leave the personal grower? Based on all of the research I've read and my limited experience (5 grows) — turn it up and leave it on. Like numerous researchers have demonstrated, plant yield, plant quality, crop yield, and crop quality increase as light levels increase. It's not quite linear but it's very close.

I aim for the cannabis light saturation point of 800-1000µmols, strain dependent, no CO2. I've run as high as 1200 and ended up with foxtails and, in a more recent grow (Gorilla Glue), did well as long as PPFD was < 950µmols. At that level, one of the colas bent - these were big colas, about 2" wide at the time and it bent at about a 45° angle.

Another grow was at 63 DLI for about a week and then 57± for the next month while my most recent grow was 60± from day 40 to day 110. All of them had a tremendous amount of growth and yields of 17 to 20 ounces, despite thrips infestations.

Light's the driver - more light, more food, more buds.

Lol man he’s so stone cold matter of fact about it it’s comforting, like having your grandfather explain some really common sense stuff to you. The last I remember was he was essentially saying they really haven’t found cannabis’ limit when it comes to light. They’ve been limited by every other factor, but the more light they throw, the more it takes it.

Which if you think about the existence of megafauna and flora makes sense.. A lot of plants seem to only be limited by their environments, not their biology. If they were given unlimited access to all of the required resources and had no competition, I strongly suspect the smallest blade of grass could grow into the largest redwood. (Or something similar to that incredibly rough analogy )

 

[Gee64]

We care about the PPFD while choosing a light for the grow, but is it " the highest PPFD, the best"? There has no photon density limits?

My priorities go like this

1) Quality of the spectrum
2) Quality of the environment
3) Size and health of the rootball
4) .. oh dang, volume of light didn't make the top 3. Maybe without a good spectrum in a good environment to give you a good rootball that can handle tons of light, tons of light isn't that important

 

[Delps8]

Lol man he’s so stone cold matter of fact about it it’s comforting, like having your grandfather explain some really common sense stuff to you. The last I remember was he was essentially saying they really haven’t found cannabis’ limit when it comes to light. They’ve been limited by every other factor, but the more light they throw, the more it takes it.

Which if you think about the existence of megafauna and flora makes sense.. A lot of plants seem to only be limited by their environments, not their biology. If they were given unlimited access to all of the required resources and had no competition, I strongly suspect the smallest blade of grass could grow into the largest redwood. (Or something similar to that incredibly rough analogy )

Dunno about lawn grass growing as tall as bamboo but your point is well taken - something has to be a limiting factor in how we grow and, in a lot of cases, it's that grower do not feed their plants enough light.

Re. Grandpa - good point. Bugbee's got the right looks, hair, voice, and mannerisms. I've talked to Apogee tech support a few times (I got my meter recalibrated and I've called them with questions about grow lighting) and the CSR's I spoke with said, to use a phrase, what you see is what you get. According to them, he a very down to earth (pardon the pun) guy.

 

[ViparSpectra]

Lol man he’s so stone cold matter of fact about it it’s comforting, like having your grandfather explain some really common sense stuff to you. The last I remember was he was essentially saying they really haven’t found cannabis’ limit when it comes to light. They’ve been limited by every other factor, but the more light they throw, the more it takes it.

Which if you think about the existence of megafauna and flora makes sense.. A lot of plants seem to only be limited by their environments, not their biology. If they were given unlimited access to all of the required resources and had no competition, I strongly suspect the smallest blade of grass could grow into the largest redwood. (Or something similar to that incredibly rough analogy )

Thanks for sharing. The environment plays an important role in the whole planting, we should seek a balance instead of blindly pursuing high values.

 

[ViparSpectra]

My priorities go like this

1) Quality of the spectrum
2) Quality of the environment
3) Size and health of the rootball
4) .. oh dang, volume of light didn't make the top 3. Maybe without a good spectrum in a good environment to give you a good rootball that can handle tons of light, tons of light isn't that important

Thanks for your opinion. Yes, so all of our lights are the full-spectrum that can be used at the different growth stages.