Light timer cockup help

Mumbeltypeg

Well-Known Member
Hi folks.. I need some advice here.
I added an extra light a week ago at week 3 of flower and I missed a couple of old programs on the timer and so the lights have been coming on and off through the night and my poor girls have started kicking out vegetative growth and the buds have stopped developing.. I have fixed the light issue just now but I am worried this is too severe an issue to recover from.. any advice from someone who has done this rookie mistake would be most welcome.
Will they kick back into flower again or do I need to scrap and start again?
 

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Delps8

Well-Known Member
I really hope you get this sorted. I had something similar when I did a grow in 2017 and it was painful.

We got a power outage and I mucked up setting the timer. Lights went crazy, as did the plant. I binned the plant (it was 3'+) and archived my tent for a few years.

Since I started growing again, it's all digital - fans, lights, pumps, etc. Two and half years and zero issues. I've been a software engineer since the late 80's and have watched many technologies unfold over the years. Until maybe 5 years ago, this level of tech was dogshit bad. No longer. It's cheap and highly reliable.

If you're in the market, check out the Kasa smart strips. Between the Smart Strips, Wyze security cameras, and a AC Infinity Controller 69, you can set it and forget it and monitor it from anywhere, anytime.
 

Grojak

Well-Known Member
It only took one time of this very same thing happening years ago to convert to digital for flower. I had 1 of the 15 min interval pegs in the wrong position took me a week to figure it out.

I still have 10 year old analog timers in veg but never again for flower.
 

Mumbeltypeg

Well-Known Member
I decided to give them 24 hours of dark and then flip back to the flower schedule.. my poor girls.. was all set to be my best grow yet too.. would have been an 8 pound grow easy..
when I switch the lights back on I’m going to give them a week of lights dimmed 50% I figure a little less photosynthesis work for them will help them recover from the stress a bit.
 
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Delps8

Well-Known Member
I decided to give them 24 hours of dark and then flip back to the flower schedule.. my poor girls.. was all set to be my best grow yet too.. would have been an 8 pound grow easy..
when I switch the lights back on I’m going to give them a week of lights dimmed 50% I figure a little less photosynthesis work for them will help them recover from the stress a bit.
Cui bono?

Sometime growers do things that they think will be better for the plant but it ends up that the only positive outcome is that the grower feels better. Lacking any evidence that the plant is suffering from too much light, what is the rationale behind reducing light levels?

The issue is that the photoperiod changed. Plants go into flower when the ratio of certain hormones changes. Your plants are exhibiting a completely normal response to that change. Unless there are symptoms of light stress, I can't think of how a plant benefits from getting less light. I'm not saying don't be pro-active - I am was highly ranked in Helicopter Plant Daddy standings for my first few grows - but I don't think less light is the correct approach.

Generally speaking, organisms don't do better with less food. When you reduce light levels to a plant, that reduces the amount of food that the plant can generate. In turn, that reduces the plants' ability to, first, respond to stresses and, second, to grow.

The light saturation point for cannabis is 800-1000µmols and the light compensation point (the lowest amount of light that a leaf can receive and still contribute photosynthetically) is 64µmols. Cannabis will survive if the PPFD is between those values and, as light levels increase, the plant is more able to survive and thrive.

I'm not a fan of growing by dimmer % (I'm still on the Helicopter Plant Daddy ladder but waaay down the list). I urge grower to use a light meter. If you've got the $$, a PAR meter removes all doubt but a $32 Uni-T Bluetooth light meter is money very well spent.

No question about it that we can grow without it and a lot of growers do so. OTOH, there's so much data that indicates that crop quality and yield are directly tied to light levels that the additional cost ($32 in the US) and time involved in monitoring light levels is paid off handsomely.

Just my tuppence.
 

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Mumbeltypeg

Well-Known Member
Cui bono?

Sometime growers do things that they think will be better for the plant but it ends up that the only positive outcome is that the grower feels better. Lacking any evidence that the plant is suffering from too much light, what is the rationale behind reducing light levels?

The issue is that the photoperiod changed. Plants go into flower when the ratio of certain hormones changes. Your plants are exhibiting a completely normal response to that change. Unless there are symptoms of light stress, I can't think of how a plant benefits from getting less light. I'm not saying don't be pro-active - I am was highly ranked in Helicopter Plant Daddy standings for my first few grows - but I don't think less light is the correct approach.

Generally speaking, organisms don't do better with less food. When you reduce light levels to a plant, that reduces the amount of food that the plant can generate. In turn, that reduces the plants' ability to, first, respond to stresses and, second, to grow.

The light saturation point for cannabis is 800-1000µmols and the light compensation point (the lowest amount of light that a leaf can receive and still contribute photosynthetically) is 64µmols. Cannabis will survive if the PPFD is between those values and, as light levels increase, the plant is more able to survive and thrive.

I'm not a fan of growing by dimmer % (I'm still on the Helicopter Plant Daddy ladder but waaay down the list). I urge grower to use a light meter. If you've got the $$, a PAR meter removes all doubt but a $32 Uni-T Bluetooth light meter is money very well spent.

No question about it that we can grow without it and a lot of growers do so. OTOH, there's so much data that indicates that crop quality and yield are directly tied to light levels that the additional cost ($32 in the US) and time involved in monitoring light levels is paid off handsomely.

Just my tuppence.
I appreciate that, I use a par meter and usually am up around 1600par around the centre of my lights.. I use co2 and have my temps around 31.C. My rationale by dropping 50% for the first week after I give it some dark was to ease the amount of photosynthesis work the plants have to do.. I’ll admit it’s just my own idea with no real science behind it, just my own idea.. but I thought perhaps letting them slow down a bit while they revert back to flowering might be a good idea.. and to put the brakes on the vegetative growth as much as possible.
Then after I have given a week or so and see signs of flowering kicking back into gear I will up all parameters again and kick it into gear.
Thoughts?
I really appreciate you putting the time into that answer by the way.
 

Mumbeltypeg

Well-Known Member
I really hope you get this sorted. I had something similar when I did a grow in 2017 and it was painful.

We got a power outage and I mucked up setting the timer. Lights went crazy, as did the plant. I binned the plant (it was 3'+) and archived my tent for a few years.

Since I started growing again, it's all digital - fans, lights, pumps, etc. Two and half years and zero issues. I've been a software engineer since the late 80's and have watched many technologies unfold over the years. Until maybe 5 years ago, this level of tech was dogshit bad. No longer. It's cheap and highly reliable.

If you're in the market, check out the Kasa smart strips. Between the Smart Strips, Wyze security cameras, and a AC Infinity Controller 69, you can set it and forget it and monitor it from anywhere, anytime.
I use a climate control system, and a split system AC, cO2 generator, humidity controller, par sensor, take regular readings of LST, chiller to keep res temp stable.. this light fuck up was such a rookie mistake.
 

shnkrmn

Well-Known Member
I also think you want them as vigorous as possible recovering from reveg If you slow them down it'll just do exactly that, slow them down.
 

shnkrmn

Well-Known Member
Heres when I noticed the problem:


Here's how they finished:

 

Delps8

Well-Known Member
I appreciate that, I use a par meter and usually am up around 1600par around the centre of my lights.. I use co2 and have my temps around 31.C. My rationale by dropping 50% for the first week after I give it some dark was to ease the amount of photosynthesis work the plants have to do.. I’ll admit it’s just my own idea with no real science behind it, just my own idea.. but I thought perhaps letting them slow down a bit while they revert back to flowering might be a good idea.. and to put the brakes on the vegetative growth as much as possible.
Then after I have given a week or so and see signs of flowering kicking back into gear I will up all parameters again and kick it into gear.
Thoughts?
I really appreciate you putting the time into that answer by the way.
1600 and 31C - life in the fast lane!

The PPFD is great but the temps give me pause. I've attached "the Chandra paper" for your light reading (no pun intended). At those temps, net photosynthesis is really rolling off, one, but, second, my thinking about temperature is that you're getting a lot of mass at those temps but THC content might be diminished.

From the paper:

Chandra - Cannabis photosynthesis vs PPFD and Temp.png


Yeh, you're right at the peak - careful up there! :-)

That chart is helpful but it's important that the value that's plotted is "Net Photosynthesis" but we're not harvesting net photosynthesis. If you grind through the papers that I've attached, there's lots of evidence that more is better but the PPFD's that they're working with are lower than what you're using.

FWIW, in a few of his vids, Bugbee has stated that 1200 and 1200 are "optimal" but that was economic optimum. One phrase he used is that you can bump up your PPFD/DLI by 30% but yield only goes up by 15%.

Zheng and Westmoreland, who are coauthors on some of those papers, are former students of Bugbee, so it's one big, happy family.

Finally item - the site for this page is by the fellow who created HydroBuddy so he earned his chops in my book.
 

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Delps8

Well-Known Member
I use a climate control system, and a split system AC, cO2 generator, humidity controller, par sensor, take regular readings of LST, chiller to keep res temp stable.. this light fuck up was such a rookie mistake.
Very nice set up! I'm jealous - I grow in a 2' x 4' tent in a garage in Southern CA. Fortunately, temps are mild here. If I try to grow in the summer, I've got to run a 14k BTU A/C unit. Our KwH prices here are very high so it's $500 a month if I run it. :-(

Since you've got a PAR meter, you might want to check out the "Clear Sky" app published by Apogee. It's on iOS, don't know about Android, and it's a good check for your PAR meter.
 

Mumbeltypeg

Well-Known Member
Heres when I noticed the problem:


Here's how they finished:

Thanks bud, that gives me some hope yet
 

Mumbeltypeg

Well-Known Member
1600 and 31C - life in the fast lane!

The PPFD is great but the temps give me pause. I've attached "the Chandra paper" for your light reading (no pun intended). At those temps, net photosynthesis is really rolling off, one, but, second, my thinking about temperature is that you're getting a lot of mass at those temps but THC content might be diminished.

From the paper:

View attachment 5349124


Yeh, you're right at the peak - careful up there! :-)

That chart is helpful but it's important that the value that's plotted is "Net Photosynthesis" but we're not harvesting net photosynthesis. If you grind through the papers that I've attached, there's lots of evidence that more is better but the PPFD's that they're working with are lower than what you're using.

FWIW, in a few of his vids, Bugbee has stated that 1200 and 1200 are "optimal" but that was economic optimum. One phrase he used is that you can bump up your PPFD/DLI by 30% but yield only goes up by 15%.

Zheng and Westmoreland, who are coauthors on some of those papers, are former students of Bugbee, so it's one big, happy family.

Finally item - the site for this page is by the fellow who created HydroBuddy so he earned his chops in my book.
Love bugbees stuff.. was thinking about taking his online course last year but haven’t gotten to it yet.. have burned through all the free videos I can find multiple times. I know I’m pushing them pretty hard at these parameters but boy it has paid off and the size and quality is right up there.. I guess I was thinking that’s why if I slowed them down a bit they might recuperate better.. like letting them walk and catch their breath, but analogies only get you so far. I’ll keep pushing them and just see how they go.
Thanks for all the refs.
 
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