Sweet Yet Haunted Seedsman's Purple Ghost Candy Comparative

[Keffka]

It's the practicalities of this that I'm grappling with. We have what is called "loadshedding" in South Africa. That is because our government owned power supplier is unable to generate sufficient electricity for the country and so they share it out by area and we are without power for between 2.5 to over 12 hours a day every day. This is usually for between 2.5 to 5 hour slots of no power.

Thank you! I don't want to clutter Otter's journal with my loadshedding issues, but I do need the help.
I did not do maths in highschool. You can't imagine how difficult it is to try maths if you haven't learnt it. Adding to the confusion is that some people quote PAR and others PPFD

I believe in you Otter, you will find the way. Are you working in PAR throughout the grow? What PPFD is equal to 300 PAR someone please?

ya see, now here is PPFD again

Ok! I think I may have been giving my plants too much light. That would also explain deficiencies wouldn't it?

This!

This!

Gee Man it's not possible for me to control my VPD in my living room.

Given the loadshedding shituation and the fact that I grow my weed on my living room table in LOS, what is your suggestion to me regarding DLI and PPFD / PAR please? Shed and I chatted in my last journal about exactly this and here's what we concluded at the time.

So now I need to figure out how much PPFD / PAR at what stage of growth and for how many hours per day, given the loadshedding complications in the mix, but as I say, I don't want to clutter Otter's journal unless this is of interest to others. We could shift this discussion to my last journal if it is too much?

Understood, thank you.

PAR refers to the wavelengths (or color) of light that a plant can use for photosynthesis. PPFD refers to the amount of PAR (the color of light it can use for photosynthesis) that is hitting the plants.

PAR is your color PPFD is your quantity. So if you have 300 ppfd that means your plant is getting 300 moles of PAR that it can use for photosynthesis.

If you’re using a growing light, your PAR should already be squared away. Your PPFD is what you want to increase/decrease which in turn increases/decreases your DLI because DLI is the total amount of PPFD you get over 24 hours, and PPFD is the amount of PAR hitting the plant every second.

 

[Keffka]

PAR (usable light) >

PPFD (amount of usable light hitting your plants every second) >

DLI (amount of usable light hitting your plants every 24 hours)

 

[Azimuth]

I found it interesting that The Rev strongly advocates for very cool light (>5k) than warm (<3k) in flower. In my box I transition them from cool to warm based on my bulb choices.

I seem to remember a discussion somewhere on here that there is a difference in buds and trichs depending on that choice.

 

[Grand Daddy Black]

I found it interesting that The Rev strongly advocates for very cool light (>5k) than warm (<3k) in flower.

Azi, could you explain this "cool" vs. "warm" reference. What does 5k and 3k refer to?

 

[Melville Hobbes]

I found it interesting that The Rev strongly advocates for very cool light (>5k) than warm (<3k) in flower. In my box I transition them from cool to warm based on my bulb choices.

I seem to remember a discussion somewhere on here that there is a difference in buds and trichs depending on that choice.

As far as I remember a cooler spectrum yields slightly less, but encourages denser buds, and slightly higher cannabinoid production.
What I read about that was from before LEDs really took off, and was referring to results from continuing to use CMH through flower instead of switching to HPS.

 

[Azimuth]

Azi, could you explain this "cool" vs. "warm" reference. What does 5k and 3k refer to?

It's often referred to as warm or cool light on the box your light bulbs come in. There will also be a small graph showing where on the scale that one lands. Think of a cool blue light like florescent and a warm, more reddish one for your living room.

The color is supposed to affect growth in plants so many use a cool, blueish light in veg (something above 4,000k or so. Mine are 5,000k for veg and 3,000k for mid/late flower.

The color choice dictates frost and stretch, or something along those lines.

 

[Azimuth]

As far as I remember a cooler spectrum yields slightly less, but encourages denser buds, and slightly higher cannabinoid production.
What I read about that was from before LEDs really took off, and was referring to results from continuing to use CMH through flower instead of switching to HPS.

I think you're right on that. The Rev still swears by MH in flower.

I use 3, 6 light bathroom vanity light strips so I can mix'n match. So I do the first set of 6 as cool 5,000k bulbs, the next 6 50/50, and the last set as all 3,000k.

 

[StoneOtter]

ya see, now here is PPFD again

It's confusing for sure Carmen! Here's the key in addition to Keffka's well done explanation. PPFD of PAR. The amount of light. When I started using the terms like, "I have 300 ppfd of PAR" I started to understand that part. We do see the terms used all over the place and it is most certainly confusing!
PPFD gets changed for the plants needs, it's amplitude. PAR is the source your amplifing what is a section of the light spectrum. Keep in mind light is a vibration. I don't feel it necessary to know all about that. Just to believe.
How about now?

 

[Carmen Ray]

PAR refers to the wavelengths (or color) of light that a plant can use for photosynthesis. PPFD refers to the amount of PAR (the color of light it can use for photosynthesis) that is hitting the plants.

PAR is your color PPFD is your quantity. So if you have 300 ppfd that means your plant is getting 300 moles of PAR that it can use for photosynthesis.

If you’re using a growing light, your PAR should already be squared away. Your PPFD is what you want to increase/decrease which in turn increases/decreases your DLI because DLI is the total amount of PPFD you get over 24 hours, and PPFD is the amount of PAR hitting the plant every second.

Thank you for explaining the difference between them. Those who have gone before you must think I am as thick as a plank

PAR (usable light) >

PPFD (amount of usable light hitting your plants every second) >

DLI (amount of usable light hitting your plants every 24 hours)

I still don't know how much PPFD to give my plants to achieve the right amount of DLI. This is what I concluded in my journal but I don't recall how or why I reached the following conclusion or if it is correct.

I shall have to ponder this a while. The thought of saving on electricity cost is tempting. I could try it and see how it goes. So I'd keep the power at 50 % and the lights on 24/0, and then when we get hit with heavy loadshedding I compensate by raising the power.

It's confusing for sure Carmen! Here's the key in addition to Keffka's well done explanation. PPFD of PAR. The amount of light. When I started using the terms like, "I have 300 ppfd of PAR" I started to understand that part. We do see the terms used all over the place and it is most certainly confusing!
PPFD gets changed for the plants needs, it's amplitude. PAR is the source your amplifing what is a section of the light spectrum. Keep in mind light is a vibration. I don't feel it necessary to know all about that. Just to believe.
How about now?

Thank you Otter. I misunderstood and thought you were giving your measurements in PAR instead of PPFD?

This subject does my head in

After having read the manual over again and feeling none the wiser, I would be very grateful if someone could help me work out or tell me I need X PPFD for 12 hours to achieve the desired DLI, or 15 hours, or 18 hours, or 24 hours, so that I can judge when and how to flip the dial and the switch. Is this possible to figure out? The manual doesn't go into the DLI but it does have a recommended PPFD map.

 

[InTheShed]

Seedling looks happy as a clam Otter!

I still don't know how much PPFD to give my plants to achieve the right amount of DLI.

The Photone app does that for you as you slide through the readouts. The DLI page has an "hours" setting on top you can change, and the app will multiply your PPFD x the hours of light you're able to provide (given load shedding) to give you the DLI.

If you have a DLI target, you can increase or decrease your light hours or your PPFD (by raising/lowering the light, or increasing/decreasing the brightness) to hit that target.

They don't teach multiplication until high school, and it's optional?

 

[Gee64]

I found it interesting that The Rev strongly advocates for very cool light (>5k) than warm (<3k) in flower. In my box I transition them from cool to warm based on my bulb choices.

I seem to remember a discussion somewhere on here that there is a difference in buds and trichs depending on that choice.

Blue light opens stomata farther. In small pots with no soil carbon in them, like the ones Rev uses, all the carbon MUST come from the atmosphere, so blue light allows for deeper breaths to grab more atmospheric CO2. If you grow with CO2 this will help as well.

 

[JiggiLotus]

Seedling looks happy as a clam Otter!

The Photone app does that for you as you slide through the readouts. The DLI page has an "hours" setting on top you can change, and the app will multiply your PPFD x the hours of light you're able to provide (given load shedding) to give you the DLI.

If you have a DLI target, you can increase or decrease your light hours or your PPFD (by raising/lowering the light, or increasing/decreasing the brightness) to hit that target.

They don't teach multiplication until high school, and it's optional?

I use that same photon app. It has all them units/measurements on it. Just swipe to what you want and it also allows you to choose 12, 16, 18+ hrs to get the correct dial in.

 

[Carmen Ray]

Seedling looks happy as a clam Otter!

The Photone app does that for you as you slide through the readouts. The DLI page has an "hours" setting on top you can change, and the app will multiply your PPFD x the hours of light you're able to provide (given load shedding) to give you the DLI.

Thanks Shed. You're right. The DLI reading shows you how much PPFD you have and what % is being achieved at 12 / 18 / 24 hours. The Photone app reads the light. However, if I am overdoing the PPFD it's not going to tell me what settings to change to. I have to figure that out.

If you have a DLI target, you can increase or decrease your light hours or your PPFD (by raising/lowering the light, or increasing/decreasing the brightness) to hit that target.

I get this in theory but I still need to know the actual optimal distance and settings. Vipar Spectra have a PPFD map with recommended distances, so I think I just need to work out the brightness and number of hours. Or what?

They don't teach multiplication until high school, and it's optional?

Yes I learnt multiplication and simple problems fifty years ago and I rely on a calculator for all arithmetic. I was taught to type, cook and sew. That is what was deemed important back in the day. I did also learn two languages, geography, biology and art. That's it.

Subsequently I went on to get 98 % pass in a Sound & Lighting Engineering course before I changed my diploma to Fine Art. I could understand lighting then but no longer. I can't explain why my brain no longer wants to take in / retain technical information other than to say that not everyone has the same abilities and my brain is aging.

If someone can give me the formula for working out how much PPFD I need at what distance and for how many hours to achieve the correct DLI I can try to figure it out on the calculator. I'd like to have the plan in place so that I know what height and brightness for how long beforehand, so that I'm not raising and lowering lights several times per day.

Yes maths was and is optional. A great pity.

 

[StoneOtter]

Thank you Otter. I misunderstood and thought you were giving your measurements in PAR instead of PPFD?

Because I said it in slang basically! Sorry! I'll try to not act as I've seen. It took me years to figure that for sure. I'm slow.

The chart below I found I have to believe until proven otherwise. This is my first run with this stuff.
Today my light is set to 300 ppfd of PAR. I set the dial on the light until it read 300 on the phone running Photone. Then when I swiped left or right I chose the number of hours the light is on. Then I read DLI, and it's dead on to the what the charts say. So the meter app works that way.

With the number of hours set(18 or 12 for me) in the app you can use either the DLI or ppfd of PAR pages to adjust or watch the intensity of your light.

So if I'm in seedling stage I want to set my light somewhere between 100 and 300 ppfd of PAR. That will give you the proper DLI found on the chart below also.

I don't use both charts. They just back each other up with information from what I can tell. Well either or both, it doesn't matter. Pick one if it tickles your fancy and get used it.


cannabis plant:

Growth Phase	PAR Level (PPFD)
Seedling / Clone	100 – 300
Vegetative	250 – 600
Bloom / Flowering	500 – 1050

Growth Phase	Photoperiod (h)
Seedling / Clone	16 – 24
Vegetative	16 – 24
Bloom / Flowering	10 – 13
Maturing	10 – 14

 

[StoneOtter]

7 DAYS OLD PICS UPDATE! MAKES ME WEEK IN THE WEEDS!

Good day all! This little spookable's having a nice time making roots and shoots!
@SeedsMan made a fine work here! She's coming on strong!
Have a lookee!

IMG_0884.jpeg

• StoneOtter
• Mar 17, 2024

Purple Ghost Candy

IMG_0885.jpeg

• StoneOtter
• Mar 17, 2024

Purple Ghost Candy

 

[Keffka]

Thanks Shed. You're right. The DLI reading shows you how much PPFD you have and what % is being achieved at 12 / 18 / 24 hours. The Photone app reads the light. However, if I am overdoing the PPFD it's not going to tell me what settings to change to. I have to figure that out.

I get this in theory but I still need to know the actual optimal distance and settings. Vipar Spectra have a PPFD map with recommended distances, so I think I just need to work out the brightness and number of hours. Or what?

Yes I learnt multiplication and simple problems fifty years ago and I rely on a calculator for all arithmetic. I was taught to type, cook and sew. That is what was deemed important back in the day. I did also learn two languages, geography, biology and art. That's it.

Subsequently I went on to get 98 % pass in a Sound & Lighting Engineering course before I changed my diploma to Fine Art. I could understand lighting then but no longer. I can't explain why my brain no longer wants to take in / retain technical information other than to say that not everyone has the same abilities and my brain is aging.

If someone can give me the formula for working out how much PPFD I need at what distance and for how many hours to achieve the correct DLI I can try to figure it out on the calculator. I'd like to have the plan in place so that I know what height and brightness for how long beforehand, so that I'm not raising and lowering lights several times per day.

Yes maths was and is optional. A great pity.

Here’s your formula:

1. Note down the number of light hours.
2. Note down the PPFD value
3. Multiply the light hours by PPFD.
4. Multiply the result by 3600.
5. Next, divide the result from step 4 by 100,000.
6. The result is the DLI value in mol/m²/day

We can’t give you the actual numbers you’ll need because they vary from grow to grow. An average set of numbers for an early veg plant would be something like

18 light hours (the amount of hours the light is on)

300 PPFD (this 300 PPFD is achieved on my light by running it at 25% and having it 28 inches from the plants. Or I could run it at 50% and have it at 42 inches above the plants)

This is where those light maps help, they tell you what the PPFD should be at different heights and intensities. We use a meter just to make sure. If our lights aren’t working properly or something is amiss those PPFD maps don’t mean much. However they’re a good starting point

 

[Gee64]

Here’s your formula:

1. Note down the number of light hours.
2. Note down the PPFD value
3. Multiply the light hours by PPFD.
4. Multiply the result by 3600.
5. Next, divide the result from step 4 by 100,000.
6. The result is the DLI value in mol/m²/day

We can’t give you the actual numbers you’ll need because they vary from grow to grow. An average set of numbers for an early veg plant would be something like

18 light hours (the amount of hours the light is on)

300 PPFD (this 300 PPFD is achieved on my light by running it at 25% and having it 28 inches from the plants. Or I could run it at 50% and have it at 42 inches above the plants)

This is where those light maps help, they tell you what the PPFD should be at different heights and intensities

@Carmen Ray If you google "DLI calculator" you get a bunch of them. Then just put in the PPFD and hours and DLI is calculated automatically.

You can use it to run pretend scenarios until you find a PPFD/DLI that the plant can handle that gives you a decent DLI.

For reference, the Durban Poison that I have grown a lot of and know well, doesn't like more than 950 ppfd in flower. More DLI/PPFD and I get hermies.

Right now I'm in deep veg prepping to flip at a PPFD of 650. That gives me this....

So a DLI of 42.12. When I flip the PPFD will initially stay at 650 until it gradually increases to 950 after stretch is done and vertical growth slows. So immediately after stretch my DLI will drop like this...

28.8 is low so I will gently increase ppfd in 50 ppfd increments over 3 weeks, and I need 300 more ppfd to get to 950, so I will shoot for an increase of 100 ppfd per week, so 2 adjustments of 50 per week, until stretch is done.

The plant usually does this on it's own, or you may even have to reduce the light intensity as it stretches towards the light, which gets it into a higher PPFD zone, but once stretch is done I hope and aim for this....

I can run a higher PPFD/DLI on this strain, but it will hermie pretty much every time, and 950PPFD, a DLI of 42, is right in the recommended ballpark but more importantly, the plant is happiest.

Brix soar. Buds get huge. And it's very low risk.


So using the calculator before hand to plot a course has great value and no math

As a side note, I didn't plan on being at 650 PPFD, I used VPD to dial in my light intensity and it worked out to be 650.

I use VPD to dial it in during flower and it always ends up at 950-1000. Some phenos can handle more light. With Durban, the fluffier the pheno, the more light it can handle. The nuggy phenos are all happy at 950 PPFD.

So at 950 in full bloom I have a 2 degree difference between leaf temp and air temp, and at 76F degrees with 74F leaf temps, and an RH of 48, i get a VPD of 1.40, which is dead on for good flowering without hermie stress.

So VPD got me to 950, not following the chart blindly, but the chart numbers should be the goals you aim for.

I know you can't use VPD in your dining room, but it's good to see how it all ties together. 2 very different paths to the same destination.

VPD is more to learn, but the safer path. Understanding VPD teaches you how a plant actually works, whereas a DLI target is just a number. Some plants want more, some less. This is where VPD excels over DLI/PPFD but.... If you dial it in with VPD, then take a PPFD/DLI reading, you now have an accurate DLI/PPFD
target for that strain in the future.

As for your loadshedding woes, You are kind of stuck with what you have unless you can find a backup power source for your light.

 

[Gee64]

Stone, The baby Girls look splendid!. This should be a great run!

 

[StoneOtter]

Stone, The baby Girls look splendid!. This should be a great run!

Thanks Gee! I hope to keep focus as we go! And that the grow Gods are kind! She's getting her feet rooted. Gave her first full water yesterday. I gotta go see how she did with it!

 

[Roy Growin]

Azi, could you explain this "cool" vs. "warm" reference. What does 5k and 3k refer to?

The reason it is called colour temperature is because it is measured by the colour Tungsten gives off at a given temperature [Kelvin]
At 2700K, Tungsten glows orange; 5600K it glows blue, becoming more white up to 6500K
This is because the Tungsten is holding more energy, thus giving off a stronger/higher frequency light, the blue end of spectrum
The reason the lower K is 'warm' is because it is closer to infra-red, ie heat, whereas pure blue light carries almost no heat so described as 'cool'