Or_Gro
Well-Known Member
ThanksCertainly will.
High Light efficiency tests (TEKNIK) - 2.47 umol/j CRI 94.2
- Thread starter Prawn Connery
- Start date
Prawn Connery
Well-Known Member
Took some readings from @Frank Cannon 's light cannon today: non-UV boards with added 6% UVB reptile bulbs
Arcadia 6% T5 reptile bulb - a lot of the good stuff (UVB/A) is below 380nm. Big green spike in the middle with lots of blue, cyan and 610nm red.
Here's what the 12% Arcadia looks like measured by the Journal of Zoo and Aquarium Research. A lot more blue and double the UV - it gives you an idea of what the 6% looks like above if you look below 380nm
8x High Light red boards with 4x 22" T5 Arcadias. UVA/B below 380nm obviously can't be measured on this spectrometer
And how Frank's setup compares to straight High Light near-UV boards: green = High Reds + reptile bulbs; pink line = High Light near-UV
Arcadia 6% T5 reptile bulb - a lot of the good stuff (UVB/A) is below 380nm. Big green spike in the middle with lots of blue, cyan and 610nm red.
Here's what the 12% Arcadia looks like measured by the Journal of Zoo and Aquarium Research. A lot more blue and double the UV - it gives you an idea of what the 6% looks like above if you look below 380nm
8x High Light red boards with 4x 22" T5 Arcadias. UVA/B below 380nm obviously can't be measured on this spectrometer
And how Frank's setup compares to straight High Light near-UV boards: green = High Reds + reptile bulbs; pink line = High Light near-UV
Last edited:
Frank Cannon
Well-Known Member
Here's the PPF measurements recorded also.
I have my setup running 2 x pairs (4 boards) off a HLG-480 driver.
480w at the wall - say 110w per panel is:
975 ppfd / 60500 lux at 12 inches
890 ppfd / 55000 lux at 15 inches
300w at thewall - say 70w per panel is:
600 ppfd / 37000 lux at 12 inches
500 ppfd / 31000 lux at 15 inches
I have my setup running 2 x pairs (4 boards) off a HLG-480 driver.
480w at the wall - say 110w per panel is:
975 ppfd / 60500 lux at 12 inches
890 ppfd / 55000 lux at 15 inches
300w at thewall - say 70w per panel is:
600 ppfd / 37000 lux at 12 inches
500 ppfd / 31000 lux at 15 inches
Frank Cannon
Well-Known Member
They seem to at least be growing
![20190704_165008[2].jpg](/data/attachments/3461/3461680-04e87c3a601825e8153fae696c655023.jpg)
![20190704_163754[1].jpg](/data/attachments/3461/3461685-da1aac7cc12ac8f8ab6955849be0696e.jpg)
led1k
Well-Known Member
Damn they thick!!
Any plans for defol?
Frank Cannon
Well-Known Member
hybridway2
Amare Shill
Limited stretch?
Prawn Connery
Well-Known Member
They won't stretch much. I've seen the finished product under other lights and there's enough blue in there to keep stretch to a minimum. All the other plants I've seen under High Lights (including my own) have stretched less than under HPS and about the same as under other 3000K LEDs - which would make sense, as the UV boards are 2900K and Frank's 2700K boards have added UV T5s which you can just make out in the photo above.
Frank Cannon
Well-Known Member
I was a bit worried about stretch but these have been absolutely fine, a little more than the Qb96s which is good, but less than HPS.
Plus they are getting 900ppfd to help keep in check.
Plus they are getting 900ppfd to help keep in check.
Randomblame
Well-Known Member
I would only remove a few of the older (pretty big) fan leaves from the main stem to allow more light to travel deeper. Leaves help to keep the humidity high enough, they breath and they store energy, nutes and starches. So removing all the leaves means you stole her all her reserves.
That's maybe not a big issues if they get all they need with the nute soup but it at least reduce growth for a certain amount of time cause it cause a lot of stress.
So even if defol works most of the time I'm not a friend of removing all of them. A few here and there where its neccessary is okay. When the bottom side of a fan leaf is touching/hiding a side bud for instance it cause a shaded area and the evaporated water could damage that bud below. Such leaves can be removed IMO. But most of the time that's only a few of the big fan leaves from the upper half of the plant.
You work with two screens and a pretty high amount of tops so it can be neccessary to remove a few more leaves but I would still not recommend to defol them completely.
Frank Cannon
Well-Known Member
Thanks me ole gangsta cobba, well thats 2:1 from my Sensei masters so thats that
(I actually did a light defol on sat pretty much along what you just said so sounds like I am on the right track...)
(I actually did a light defol on sat pretty much along what you just said so sounds like I am on the right track...)
Prawn Connery
Well-Known Member
Here's my theory on defoliation.
The TLDR version is the more you defoliate, the more bud sites you promote, but the smaller those buds - and overall yield - will be. I've tried both ways, and the results match the theory.
Here's the reason why:
Plants will naturally defoliate themselves when they receive little or no light. We've all seen it. Lower leaves that receive no light turn yellow and die.
Stored nutrient and starches are removed from the leaf before it dies, and are transported to other parts of the plant where there is more light.
If you remove a perfectly healthy leaf, what have you just done? You've removed a source or stored energy and nutrient.
But you've also allowed light into the lower canopy which can be use for photosynthesis, right?
Not really.
Plants grow where there is light. But growth is not just limited to the amount of light available for photosynthesis. It is limited to gas exchange, moisture levels, molecular activity (warmth), nutrient availability etc. So growth is ultimately limited to root system volume and efficiency.
There is a balancing act between what the roots can supply (water, nutrient), and what the leaves can photosynthesise (using light and carbon dioxide).
When you remove leaves, you are not only removing stored energy, nutrient and moisture, you are removing areas of photosynthesis.
So the plant takes a backward step every time a leaf is removed without being able to recover that stored energy and nutrient, as well as losing a source of photosynthesis. It has to produce more leaves. Which is exactly what it does.
You need the chicken before the egg, so you can't have photosynthesis without leaves. And you can't have flowers without photosynthesis.
By defoliating, you divert resources away from flowering. You also divert growth from the upper part of the canopy to the lower part. The plant can only grow as fast as the roots and leaves allow, given a certain amount of light and warmth.
The upshot is, while you are promoting lower canopy growth, you are diverting it from the upper canopy which relies on those big old fan leaves for photosynthesis and stored moisture, nutrient and energy that would have been used for flowering growth.
If you had not defoliated, the lower canopy would have died off anyway, passing its stored energy and nutrient to other parts of the plant, where it would be used instead of having to draw additional resources from the roots.
All you've done is delayed growth by wasting and diverting resources that would have been used to promote growth on other parts of the plant (the upper canopy).
Try it one day, and I guarantee you'll see a difference in bud size and yields.
The TLDR version is the more you defoliate, the more bud sites you promote, but the smaller those buds - and overall yield - will be. I've tried both ways, and the results match the theory.
Here's the reason why:
Plants will naturally defoliate themselves when they receive little or no light. We've all seen it. Lower leaves that receive no light turn yellow and die.
Stored nutrient and starches are removed from the leaf before it dies, and are transported to other parts of the plant where there is more light.
If you remove a perfectly healthy leaf, what have you just done? You've removed a source or stored energy and nutrient.
But you've also allowed light into the lower canopy which can be use for photosynthesis, right?
Not really.
Plants grow where there is light. But growth is not just limited to the amount of light available for photosynthesis. It is limited to gas exchange, moisture levels, molecular activity (warmth), nutrient availability etc. So growth is ultimately limited to root system volume and efficiency.
There is a balancing act between what the roots can supply (water, nutrient), and what the leaves can photosynthesise (using light and carbon dioxide).
When you remove leaves, you are not only removing stored energy, nutrient and moisture, you are removing areas of photosynthesis.
So the plant takes a backward step every time a leaf is removed without being able to recover that stored energy and nutrient, as well as losing a source of photosynthesis. It has to produce more leaves. Which is exactly what it does.
You need the chicken before the egg, so you can't have photosynthesis without leaves. And you can't have flowers without photosynthesis.
By defoliating, you divert resources away from flowering. You also divert growth from the upper part of the canopy to the lower part. The plant can only grow as fast as the roots and leaves allow, given a certain amount of light and warmth.
The upshot is, while you are promoting lower canopy growth, you are diverting it from the upper canopy which relies on those big old fan leaves for photosynthesis and stored moisture, nutrient and energy that would have been used for flowering growth.
If you had not defoliated, the lower canopy would have died off anyway, passing its stored energy and nutrient to other parts of the plant, where it would be used instead of having to draw additional resources from the roots.
All you've done is delayed growth by wasting and diverting resources that would have been used to promote growth on other parts of the plant (the upper canopy).
Try it one day, and I guarantee you'll see a difference in bud size and yields.
Randomblame
Well-Known Member
I only do it 2 times! First session is mainly lollipopping and cutting a few of the upper leaves in half to remove half of the auxins and adjust growth to keep the canopy nice and even. That happens usually around day 10 from switch and the 2nd session I do when the stretch is done and I see where its needed to remove a few of the fan leaves. (~20 days later)
Frank Cannon
Well-Known Member
Hello SM1&2, I really didn't go hard on top as I know we have had this discussion before PC. What I did was a very healthy lollipop of all the struggling under growth below and into the first scrog net and then just a very judicious prune of some offending LARGE fan leaves covering some of the nicer colas (primarily because I am worried about humidity between those large leaves touching each other) at day 20 of flip and to slow down a couple of big colas that were taking off . I won't have done much damage as the bulk of the waste was from lollipopping.
Time will tell but I did heed your advice from a while ago cuzzy so I think (I hate using that word in association with me) I will be fine...
Time will tell but I did heed your advice from a while ago cuzzy so I think (I hate using that word in association with me) I will be fine...
Rocket Soul
Well-Known Member
Ill get my 2 defo cents in:
We defoliate and prune on day 1 of flower. Meaning: we take aprox 2.5 foot plants into flower, generally un topped or sparcely/late topped. Plants have been in soft vegg for almost 2 months and have plenty of roots. We remove all fan leaves and lower branches, leaving just a few upper branches and removing most growth centres. What ends up i flower is litterally a skeleton with a few controlled growth centres. Transition/stretch last us about 3 weeks, and during this we dont dont the plant enough light to stretch out very much. We get about 1-1.5 feet of stretch which creates our new flowering cannopy. Then we start turning up light levels all the way to week 11. This means:
-All flowering cannopy and branches where buds grow is brand new and extra efficient.
-we control the growth in order to have a nice cannopy, not too deep or thick, just right for growing big chunky buds. We also control when the plant uses its energy, not in stretch but in the bud building stage.
After initial defo theres no need to do a complete defo again, just some light leaf plucking and maintaining lolipoped bottoms.
Its whats been working for us, with larger plant counts its really hard to do repeated complete defo. Also it makes our buds larger, more easily trimmed and eliminates bottom larf.
We defoliate and prune on day 1 of flower. Meaning: we take aprox 2.5 foot plants into flower, generally un topped or sparcely/late topped. Plants have been in soft vegg for almost 2 months and have plenty of roots. We remove all fan leaves and lower branches, leaving just a few upper branches and removing most growth centres. What ends up i flower is litterally a skeleton with a few controlled growth centres. Transition/stretch last us about 3 weeks, and during this we dont dont the plant enough light to stretch out very much. We get about 1-1.5 feet of stretch which creates our new flowering cannopy. Then we start turning up light levels all the way to week 11. This means:
-All flowering cannopy and branches where buds grow is brand new and extra efficient.
-we control the growth in order to have a nice cannopy, not too deep or thick, just right for growing big chunky buds. We also control when the plant uses its energy, not in stretch but in the bud building stage.
After initial defo theres no need to do a complete defo again, just some light leaf plucking and maintaining lolipoped bottoms.
Its whats been working for us, with larger plant counts its really hard to do repeated complete defo. Also it makes our buds larger, more easily trimmed and eliminates bottom larf.
Prawn Connery
Well-Known Member
Plants can compensate either way. It just comes down to available space and light, and optimal use of those resources.
For example, you can veg as long as you like, but there is a cutoff point where any more veg time is wasted energy, because your yields will be the same for any given amount of light and space. There is a direct correlation between yield, optimal light, and optimal space for that light.
If you over-veg and provide optimal light and space, you waste energy.
If you veg correctly and provide optimal light and sub-optimal space, you waste energy.
If you veg correctly and provide sub-optimal light and optimal space, you waste energy.
Etc.
The most efficient form of growing under lights - proven over many years in all parts of the world - is the Sea of Green (SOG) technique. No veg time is required, no pruning is necessary, and defoliating is counter-productive.
The trade-off is plant numbers.
If you are limited to a certain number of plants, then the most efficient form of growing is the Screen of Green technique (SCROG). But it is the same principle - you are tying to do with one plant what you could do with many. Ie; create the optimal number of bud sites and room for growth for a given amount of light and space.
Scrogging is not really that efficient, because in order to achieve the above, you need longer veg times and you need to do a fair bit of pruning and training.
If you have all the time and electricity in the world, however, you can do whatever you like during veg and into flower and still get the same results: a basic grams per watt per square foot equation that is not influenced at all by veg times, except the amount of time (and energy) it takes to optimally flower within the constraints of available light and space.
We had quite a long discussion on this last year and reached the same conclusion: If plant numbers are not a factor, veg times are irrelevant to yields.
That doesn't sound right until you start to think of the SOG scenario above. If you can produce the same yields with no veg time and greater plant numbers compared to lots of veg time with only one plant, then you can see how veg time becomes irrelevant and is simply a waste of energy.
It is the same with defoliating. If you SOG, you don't defoliate - by the time those fan leaves have grown, the plant is well into flowering. So it's not such a stretch after that to realise it can be counter-productive for other grow styles, too.
But the real elephant in the room is this: We want lots of light in our flowering room to optimise photosynthesis, correct?
Now answer me this: what is better at photosynthesising - cannabis flowers or cannabis leaves?
If you answered "cannabis leaves" then you are now on your way to understanding why defoliating is counter-productive.
Plants, after all, don't just grow flowers.
For example, you can veg as long as you like, but there is a cutoff point where any more veg time is wasted energy, because your yields will be the same for any given amount of light and space. There is a direct correlation between yield, optimal light, and optimal space for that light.
If you over-veg and provide optimal light and space, you waste energy.
If you veg correctly and provide optimal light and sub-optimal space, you waste energy.
If you veg correctly and provide sub-optimal light and optimal space, you waste energy.
Etc.
The most efficient form of growing under lights - proven over many years in all parts of the world - is the Sea of Green (SOG) technique. No veg time is required, no pruning is necessary, and defoliating is counter-productive.
The trade-off is plant numbers.
If you are limited to a certain number of plants, then the most efficient form of growing is the Screen of Green technique (SCROG). But it is the same principle - you are tying to do with one plant what you could do with many. Ie; create the optimal number of bud sites and room for growth for a given amount of light and space.
Scrogging is not really that efficient, because in order to achieve the above, you need longer veg times and you need to do a fair bit of pruning and training.
If you have all the time and electricity in the world, however, you can do whatever you like during veg and into flower and still get the same results: a basic grams per watt per square foot equation that is not influenced at all by veg times, except the amount of time (and energy) it takes to optimally flower within the constraints of available light and space.
We had quite a long discussion on this last year and reached the same conclusion: If plant numbers are not a factor, veg times are irrelevant to yields.
That doesn't sound right until you start to think of the SOG scenario above. If you can produce the same yields with no veg time and greater plant numbers compared to lots of veg time with only one plant, then you can see how veg time becomes irrelevant and is simply a waste of energy.
It is the same with defoliating. If you SOG, you don't defoliate - by the time those fan leaves have grown, the plant is well into flowering. So it's not such a stretch after that to realise it can be counter-productive for other grow styles, too.
But the real elephant in the room is this: We want lots of light in our flowering room to optimise photosynthesis, correct?
Now answer me this: what is better at photosynthesising - cannabis flowers or cannabis leaves?
If you answered "cannabis leaves" then you are now on your way to understanding why defoliating is counter-productive.
Plants, after all, don't just grow flowers.
Rocket Soul
Well-Known Member
I can agree on most things here, but a little iffy on veg time doesnt matter. I think how you train and prepp your plant really matters, and you can only get some desireable plant sizes and shapes by vegging longer. But i dont think there is any automatic gain in yield by running less plants with longer vegg. But its a lot easier than running large SOGs. With 6 plants a tray you got less chances of mold or other stuff going wrong which can affect the whole grow, than if you have 25 plants a tray. Its simple math, with 4 times as many plants theres is a better chance of a weak plant getting mold.
boilingoil
Well-Known Member
Just been my experience that defo is cultivar depended. Some like it some not.
Prawn Connery
Well-Known Member
That's the point: veg time is always a trade-off between flowering space/light and plant numbers (and obviously strain dependent).
All things being equal, the more plants you grow, the less veg time you need for the same yield. If you take this to the enth degree - SOG - veg time is irrelevant.
I can agree with this to an extent - some strains are very leafy and will crowd out new bud sites - but it's usually just a matter of judiciously removing a fan leaf here or there for the greater benefit of the plant.
I don't have an issue with that. Nor do I have an issue with pruning and training, as in Rocket Soul's case (it must be noted he isn't just removing leaves but cutting branches and really shaping the plant for final flowering). I'm just not sold on wholesale defoliation as a way to improve yields by allowing more light into the lower canopy - it's not as simple as that in my experience.
PSUAGRO.
Well-Known Member
This debate is as old as the forums........but yes, plants will "self-defoliate". with high RH (in full flower) I find it beneficial to leaf strip to avoid fungal issues, not for increasing yields IMO. Granted this all comes from my outdoor practices/schooling and doesn't always translate well to indoor : ) your YMMV
Happy growing
Happy growing
Last edited: