Gradual increase in light intensity when put in flower

kingzt

Well-Known Member
Hey everyone looking for some advice when throwing plants into flower. This year iven been experiencing some light stress when i put plants into my flower room from veg. The problem is actually the light intensity in my veg room. My veg room lights are 315 lecs and my flower room has de gavitas ran at full strength. The gavitas are far away enough from the canopy so it just the plants aren’t ready for that intensity after veg After they go into the flower room they show signs off stress after a couple days. Usually takes 7-10 days for them to get back to growing strong. Last time i just vegged them longer in the flower room to get them acclimated then switched the timer.
With that being said I want to take a different approach this time. I currently can’t get more or stronger veg lights but plan on it down the road so this doesn’t happen anymore.
So when i put plants in the flower room I want to start them at a lower intensity under the gavitas, maybe like 80%(800watts). My question is how long should I run the plants under this intensity before I increase it? I won’t crank it all the way up but a more gradual increase. I just don’t want to rush the increase and the plants aren’t ready for it. Would one week at like 80% and then increase it to 90%?My guess is there is no definite answer but trial and error. Hopefully someone hasa similar experience. Any tips are greatly appreciated.
 

youraveragehorticulturist

Well-Known Member
Forum wisdom will say push as hard as you can as fast as possible. Some science dude wrote some paper about the topic. His graphs shows a gradual increase in light intensity for like 5 weeks until you hit full power.
1659213557437.png


I don't know where this one is from, but it popped up too. 6 weeks to hit max brightness, and only staying there a week.
1659213812839.png

Does anyone grow like this?
 

natureboygrower

Well-Known Member
Forum wisdom will say push as hard as you can as fast as possible. Some science dude wrote some paper about the topic. His graphs shows a gradual increase in light intensity for like 5 weeks until you hit full power.
View attachment 5172238


I don't know where this one is from, but it popped up too. 6 weeks to hit max brightness, and only staying there a week.
View attachment 5172240

Does anyone grow like this?
Kind of. First time for me pushing my light wattage. It's a new Timber bar light, so I'd like to get as much out of it as possible. I upped my wattage after 3 weeks in 12/12, not incrementally though. After 3 weeks at that higher wattage I dropped the watts by 5 and will do that 1 or 2 more times winding down towards harvest. I'm trying to use as much wattage without causing foxtailing. I'm liking the bars though, leaf temps have stayed really cool this summer.
 

Jrmtr808

Well-Known Member
If im not mistaken it has to do with the daily light intervals or DLI. When in veg your light should be set at a lower ppfd because your plants are exposed to light for a longer period of time. In flower, you will need to increase your ppfd to compensate for the reduced amount of light your plants are exposed to which will be 12 or less hours. so that you can achieve the same amount of DLI the plant needs. Lets just say for example, your plant needs a DLI of 50 to keep the growth production optimal and with 18 hours of light with 700 ppfd your plant reaches the optimal level DLI of 50. Now let’s say, you are now only giving it 12 hours of light to induce flowering. Well then you will need to up the ppfd let’s just say to 1500 with 12 hours of light to maintain to optimal level of DLI of 50.
 

kingzt

Well-Known Member
Forum wisdom will say push as hard as you can as fast as possible. Some science dude wrote some paper about the topic. His graphs shows a gradual increase in light intensity for like 5 weeks until you hit full power.
View attachment 5172238


I don't know where this one is from, but it popped up too. 6 weeks to hit max brightness, and only staying there a week.
View attachment 5172240

Does anyone grow like this?
I might have to this eventually with my veg room if I cant figure out to curb the light stress
 

PJ Diaz

Well-Known Member
Forum wisdom will say push as hard as you can as fast as possible. Some science dude wrote some paper about the topic. His graphs shows a gradual increase in light intensity for like 5 weeks until you hit full power.
View attachment 5172238


I don't know where this one is from, but it popped up too. 6 weeks to hit max brightness, and only staying there a week.
View attachment 5172240

Does anyone grow like this?
Those charts look wack to me.

I think this is a pretty good guide for lighting transition:
 

bpk419

Well-Known Member
I think this is a pretty good guide for lighting transition:
[/QUOTE]

The graph mentions increasing wattage but what about the suggested veg/flower footprints? Should the light be gradually lowered closer to the canopy during the transition or should growers allow the plants to stretch into the light while gradually increasing wattage?

The suggested veg height is 40" and the suggested flower height is 28". What would work best for this led ~ lowering by an inch every couple of days during the transition ideally hitting the 28" zone as flowers appear?
 

Muzzle2

Well-Known Member
When I go from clones to red cups, I go straight into my Gavita 1700e room. I keep the Gavitas about 42" from the bottom of the table.

I set the Gavitas to 60% and usually causes some stress, but after 1 week I bump it up 5%. When my plant reaches my optimal hieght, and I'm at 100% I transition into flower.

Usually, I would keep it from Weeks 1 - 5 at 100%, then 5 - 6 105%. Then finish off at 100%. This worked well.
Now, I tried - Week 3 105% - 1050 watts and by week 5 my Gelato's are giving me seeds/pods. Very immature, but it's everywhere. They only thing I've changed from my previous runs is higher light intensity.
 
Top