Cannabis Daily Light Integral

[OneHitDone]

And if the QBs out-yield the HPS, will you nonetheless consider the HPS to be the winner because of bud size?

This ain't a dick swinging pissing match bro - talking spectrums and intensity
Would be interesting to see an led designed with a spectrum to more closely mimic hps since that is what is known to produce the dank. Rather than constantly seeing claims of "better spectrum than HPS"

 

[Humple]

This ain't a dick swinging pissing match bro - talking spectrums and intensity
Would be interesting to see an led designed with a spectrum to more closely mimic hps since that is what is known to produce the dank. Rather than constantly seeing claims of "better spectrum than HPS"

Well I'm glad to hear it isn't a dick swinging match, but to me, that's exactly what it sounds like when bud size is so frequently mentioned - after all, bud size has absolutely no bearing on the quality of the product, but it is something that growers like to brag about, you know? (Classic pissing match material.) So my apologies if I have mistaken you. But I really see no reason why LED manufacturers should make any effort to mimic HPS spectrum, when the dank is being grown just as effectively by the current LEDs on the market. It is not a given that HID has any advantage whatsoever in that department.

 

[tomate]

The best way to find out when you have hit your max DLI for the plant you are growing is by measuring the leaf temps. There will be a clear increase of between 1-3c once the plant has taken in what it can as that unused light energy is converted to heat. A simple example would be this:

PPFD at leaf is 560 so for each hour on, it is 2 DLI. At 12hrs 20mins, the leaf temp goes up 2c indicating that the plant is done for the day. The total DLI the plant can handle at this point in its life is roughly 25. Going past this will start to cause photo-inhibition.

Has anyone ever tried that?

 

[Slinging PAR]

Has anyone ever tried that?

When it hits max DLI the leaves will start to droop so you can figure it out that way too.

 

[Rahz]

I think I'd have to lean more to spectrum
Intensity is one thing that led's definitely seem to be bringing to the table, too much in many cases...
Just as in this vid, the QB's whole hype is over high intensities. Yet the HPS side is making larger buds at a lower intensity?

What I mean is you could easily hit 1500 PPFD or more directly under a 600w HPS.

Whether HPS will produce larger but fewer buds with a similar light spread is a different thing.

 

[PurpleBuz]

This ain't a dick swinging pissing match bro - talking spectrums and intensity
Would be interesting to see an led designed with a spectrum to more closely mimic hps since that is what is known to produce the dank. Rather than constantly seeing claims of "better spectrum than HPS"

There is an amber cob available which is close to the spectrum of hps except for the infra red heater wavelengths, so have at it!
Citizen Amber COB CLU048-1212C4-22AL1K3

rather than trying to mimic an hps spectrum try understanding what it is about hps that makes it work as well as it does.

- Flowering fruiting plants really like the big fat intense band of yellow light. It bulks em up.
- Yellow\green lights as opposed to other wavelengths penetrate the canopy deeper.
- The infra red heat waves drives transpiration hard. While the resulting direct heating is hard to manage indoors it is a benefit when it can be managed.

.

 

[Schalalala]

When it hits max DLI the leaves will start to droop so you can figure it out that way too.

Do you have any source for that? Would appreciate a link.

 

[Slinging PAR]

Do you have any source for that? Would appreciate a link.

It is easy enough to try it yourself.

Besides this being the internet anyone can post anything they want whether it is correct or not. Plus not knowing the basics of plant biology is a good sign that you probably shouldn't be growing.

 

[MichiganMedGrower]

I would say droopy leaves can be from the radiant heat of the lamp not the light. We grow a high light type plant.

When I see leaves droop or point up I adjust until the are relaxed and flat. Yeah it can be trial and error. But the distance from the lamp and a happy plant is key. Part of the stable environment we try so hard to maintain.

 

[tomate]

When it hits max DLI the leaves will start to droop so you can figure it out that way too.

But if it is true that the leaf temp increases when the plant hit its max DLI this could be the more precise method to figure out what the actual max DLI the plant can handle.

Just asking if somebody that owns an ir thermometer ever tried that.

 

[MichiganMedGrower]

Doesn’t it just increase when it can’t transpire fast enough. We can’t meet a plants DLI with a lamp can we?

Is t it always possible to move the light away a little to reduce stress?

 

[Slinging PAR]

But if it is true that the leaf temp increases when the plant hit its max DLI this could be the more precise method to figure out what the actual max DLI the plant can handle.

Just asking if somebody that owns an ir thermometer ever tried that.

Either or works, and yes I have measured it with IR before. Now I don't bother as the droop is the indicator I use to adjust time on and ppfd hitting the canopy.

I would say droopy leaves can be from the radiant heat of the lamp not the light. We grow a high light type plant.

That could be a reason if that was a problem but I have this dialed in quite well so I know that the drooping is a sign that the plant is done for the day. Like everything else the plant will tell you want it needs and has enough of.

Doesn’t it just increase when it can’t transpire fast enough. We can’t meet a plants DLI with a lamp can we?

Is t it always possible to move the light away a little to reduce stress?

Heat will increase if it can't be managed by the plant and the environment. Ambient, air flow, RH, VPD, even altitude are variables in play.

Yes we can deliver minimum, optimal and maximum DLI for any plant using today's tech. 1 DLI = 275 ppfd for 1 hour. High energy plants that can handle 65 DLI works out to about 900 ppfd for 24hrs or 1800 ppfd for 12 hours.

Whether that is optimal is a different story.

 

[MichiganMedGrower]

Either or works, and yes I have measured it with IR before. Now I don't bother as the droop is the indicator I use to adjust time on and ppfd hitting the canopy.



That could be a reason if that was a problem but I have this dialed in quite well so I know that the drooping is a sign that the plant is done for the day. Like everything else the plant will tell you want it needs and has enough of.




Heat will increase if it can't be managed by the plant and the environment. Ambient, air flow, RH, VPD, even altitude are variables in play.

Yes we can deliver minimum, optimal and maximum DLI for any plant using today's tech. 1 DLI = 275 ppfd for 1 hour. High energy plants that can handle 65 DLI works out to about 900 ppfd for 24hrs or 1800 ppfd for 12 hours.

Whether that is optimal is a different story.

The optimal part is what I was being a little facetious about.

I have seen Growers blast the shit out of their plants but even the good ones with huge pretty buds can’t match the quality of a properly managed bud.

Or it’s what you want for results is probably a better way to put it. Slowly over time I can push plants a little more and now they get better from it.

 

[tomate]

I have this dialed in quite well so I know that the drooping is a sign that the plant is done for the day.

And what are the results (DLI or avg. PPFD @12h)?
With or without CO2? at which env temp and humidity? and does the DLI vary over the different growth stages?

Could you share your observations/experience with us?

 

[Slinging PAR]

And what are the results (DLI or avg. PPFD @12h)?
With or without CO2? at which env temp and humidity? and does the DLI vary over the different growth stages?

Could you share your observations/experience with us?

Sure. I seem to get punted a lot off this site but I still check back from time to time.

Optimal DLI in veg I have found is 6-20. This is because it starts off low (eg. 50-100 ppfd) and increases as the plant can handle it.

When it is time to flower, I continue to go higher ppfd to maintain 24-35 DLI. I have been able to get my flowering cycle down to 6 hours which allows for 4 flowering areas using the same power load over a 24hr cycle. 1200-1800 ppfd delivered using Vero 29s, 3000k 80 and 90 CRI. 12 per 1m2 grow area.

No CO2, just good airflow. Ambient is 21-25c. RH is 15-40% during lights on, 30-55% lights out.

I also find that blurples are the best for seedlings. Under power them to improve efficiency and balance of heat, the spectrum is good for producing short bushy plants with dark green leaves.

 

[Schalalala]

It is easy enough to try it yourself.

Besides this being the internet anyone can post anything they want whether it is correct or not. Plus not knowing the basics of plant biology is a good sign that you probably shouldn't be growing.

Wow, what scientific answer. Thanks for that valuable contribution to this topic. You don't have many friends, do you?

 

[tomate]

Optimal DLI in veg I have found is 6-20.

When it is time to flower, I continue to go higher ppfd to maintain 24-35 DLI.

So in the transition from veg to bloom you start increasing the DLI from 20-24 mol/d to about 35-38 max. Is that correct? At which stage of bloom (week) can yor plants already handle the max DLI and are you decreasing it again towards the end?

Thanks a lot for sharing this information with us.

 

[OneHitDone]

View attachment 4109447

There is an amber cob available which is close to the spectrum of hps except for the infra red heater wavelengths, so have at it!
Citizen Amber COB CLU048-1212C4-22AL1K3

rather than trying to mimic an hps spectrum try understanding what it is about hps that makes it work as well as it does.

- Flowering fruiting plants really like the big fat intense band of yellow light. It bulks em up.
- Yellow\green lights as opposed to other wavelengths penetrate the canopy deeper.
- The infra red heat waves drives transpiration hard. While the resulting direct heating is hard to manage indoors it is a benefit when it can be managed.

.

This is exactly what I was getting at, great information

 

[Slinging PAR]

Wow, what scientific answer. Thanks for that valuable contribution to this topic. You don't have many friends, do you?

Water is wet.

So in the transition from veg to bloom you start increasing the DLI from 20-24 mol/d to about 35-38 max. Is that correct? At which stage of bloom (week) can yor plants already handle the max DLI and are you decreasing it again towards the end?

Thanks a lot for sharing this information with us.

Strain variances of course can handle different amounts at different stages of life but generally yes, those are what my starting points are. Adjust as necessary up or down, it only takes about 3 or 4 days to zero in. From there you can increase anywhere from 0.2-1.2 DLI/day depending on how long you plan to veg and what the plants can handle.

I don't change anything during days with other events such as watering, feeding, etc to avoid any compounding complications as a general rule. The exception is transitions to veg from seedling and then to flower where they are left alone until fully recovered. Then they get the light hammer until droop occurs, then backed off to match the lights on time.

In bloom optimal is somewhere usually between 24 to 35 DLI. Running at max/really high DLI is inefficient. Not just for electrical but the plant has a hard time managing the problems from excessive amounts of light. If you are going for high gpw (average power usage over the course of a grow for a given area) you don't want max, you want optimal which is a balance between light power and on time.

No decrease in overall DLI towards the end. When it is ready, it gets chopped.

If you have a PAR meter, here are my rough targets for canopy ppfd using a 6hr lights on:

1100 - 24 DLI
1400 - 30 DLI
1700 - 36 DLI

 

[3GT]

Water is wet.



Strain variances of course can handle different amounts at different stages of life but generally yes, those are what my starting points are. Adjust as necessary up or down, it only takes about 3 or 4 days to zero in. From there you can increase anywhere from 0.2-1.2 DLI/day depending on how long you plan to veg and what the plants can handle.

I don't change anything during days with other events such as watering, feeding, etc to avoid any compounding complications as a general rule. The exception is transitions to veg from seedling and then to flower where they are left alone until fully recovered. Then they get the light hammer until droop occurs, then backed off to match the lights on time.

In bloom optimal is somewhere usually between 24 to 35 DLI. Running at max/really high DLI is inefficient. Not just for electrical but the plant has a hard time managing the problems from excessive amounts of light. If you are going for high gpw (average power usage over the course of a grow for a given area) you don't want max, you want optimal which is a balance between light power and on time.

No decrease in overall DLI towards the end. When it is ready, it gets chopped.

If you have a PAR meter, here are my rough targets for canopy ppfd using a 6hr lights on:

1100 - 24 DLI
1400 - 30 DLI
1700 - 36 DLI

Thanks for that! Very interesting stuff, what effect does 1700ppfd@6hrs on have on flowering times? You said you use fr as well?