Hello,
So, i switched to flowering schedule last week, and now i want to up the light intensity ( was around 40 % while vegging) because i’ve read plants demand more light during flowering phase.
So i’ve been upping the strength up a notch every few days and now i’m about 60% but my plant has again started to show light stress? ( Leaves start curling upwards at the tips ).
What should i do? Is my light too strong?
Im using KingBrite 240 W Samsung LM301H mix Epistar 660nm Red KingBright
Those poor babies they were curling up at the tips because they were light deprived , definitely learn dli and set your light to 80-100% at 14-16inches
I was just going by rule of thumb, measuring the space between each node. I thought 1 inch in between nodes is a good indicator of light being utilized. I’ll give this a read though damn.
I use lighting to manipulate node spacing too.
Photone App
Yea so i read up on this and downloaded the Photone app. Took direct readings @ DLI 12 hours of canopy in the middle and the sides using the Direct Sunlight mode.
Middle DLI readings 20, Extreme corners read 5. Now to up the DLI to 35 for the middle and 15 for the corners ill have to up my strength to 100% and i know the problem would grow worse.
Thing is i’ve only upped my light like 20 percent ( From 40 to 60%) and i’m starting to see light stress again. I had posted this earlier also when i was vegging and the reduction of light fixed the problem. Here’s the link when i was vegging:
You can see the same symptoms in the photos i took today:
Same leaf curls at the ends.
What is the problem here? It’s a White Widow photo-Strain from Ministry of Cannibis. I’m starting to suspect maybe the other factors aren’t ideal for me to increase light intensity? Gonna delve deeper into Bruce from Utahs videos.
In the mean time if any of you could shed some light?
-What strain, Seed bank, or bag seed (photo or auto)
-Age of plant
-Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF
-Vessels: Type and capacity of container (fabric, plastic, etc)
-PH and TDS of Water, Solution, runoff (if Applicable)
-PPM/TDS or EC of nutrient solution if applicable
+PPM 618 using flowering nutes
-Method used to measure PH and TDS
-Indoor or Outdoor if indoor, size of grow space
-Light system List brand and wattage/spectrum
-Actual wattage draw of lights
-Current Light Schedule
-Temps; Day, Night
-Humidity; Day, Night
-Ventilation system; Yes, No, Size
-AC, Humidifier, De-humidifier,
-Co2; Yes, No
+No
If growing Hydro some additional questions:
-DWC? RDWC? Autopots? Ebb and Flow? Other?
-Distance of liquid below net pot (DWC)
+N/A
-Temperature of reservoir
-TDS of nutrient solution
On June 3rd PPM was 618
-Amount of air to solution
Light stress is uncommon and usually presents as heat stress with damage near the tips at the canopy. As a general rule, if you can feel the heat from the light on the back of your hand (help at canopy level,) then the light is too close. Leaf curling is most often a symptom of improper pH levels. A pH that is ~6.4 in hydro is getting in the territory where iron, potassium, calcium, manganese, and boron uptake may be inhibited.
The proper light levels are:
300 PPFD for seedlings
600 PPFD for veg stage
900 PPFD for flowering stage
I looked at your support ticket info on the linked post. pH is best not allowed to creep up to 6.4. The pH range for hydro is per the following chart. 32C is pushing the high end of the temp range. Be sure that you have plenty of airflow.
Yea so i read up on this and downloaded the Photone app. Took direct readings @ DLI 12 hours of canopy in the middle and the sides using the Direct Sunlight mode.
Middle DLI readings 20, Extreme corners read 5.
Thing is i’ve only upped my light like 20 percent ( From 40 to 60%) and i’m starting to see light stress again. I had posted this earlier also when i was vegging and the reduction of light fixed the problem. Here’s the link when i was vegging:
PH has remained from 5.7 to 6.1 through out the switch to flowering schedule ( 25 March 2022 ), i am 90 perc sure its the light, could it be as Bruce Bugbee explained it? My race car doesnt have the optimum other inputs?
He’s a pretty smart dude.
another thing, is i cannot give my plant a continuous 12 hour schedule because of power outages, the problems keep adding up lol. Now what? An hour on an hour off for 24 hours to get the desired DLI? Would that work?
Ok ur light is about the same power as mine and im in a 60×60×160 tent i have mine on full blast my light hang height is around halfway up the tent or maybe abit higher than halfway i dont measure the height but my light is 280 watts for i would say lift ur light up abit more
Thanks for the info, imma head back with some experimental knowledge, i had a huge oscillating fan in my grow room, im guessing the increased light and direct wind might be the cause ( i’ve checked the roots and they’re doing fine). I think im drying my leaves out. Humidity is around 50 %
I’ve turned off the fan, lets see how the plant responds.
Also decreasing the light strength ( i.e ) with a dimmer would have the same effect as in lifting the lights? Just thinking out loud, if i raised the light and increased the strength or if i simply decreased the strength at the same height, wouldn’t it have the same effect?
Do you have the driver for your lights mounted ontop of the light inside the tent? I just mounted my driver on a rack outside my tent made such a difference on the temp.
It’s not in a tent, its a grow room, so the heat dissipates nicely, the room temp, is the ambient temp of the environment.
So turning off the fan didn’t do much. Although i can say the plants are not looking rougher than before. I can’t seem to crank my light upwards of 60 %.
Humidity 30%
Temperature 33 Deg. C
How far away is your light from the canopy?
Humidity 30%
Temp 33 Deg C.
My leaves are drying out. How am i supposed to get a good yield @ half light strength??
Still confused about the temperature, the plant was showing the same symptoms even when the temperature was 27 Day and 22 Night (Degrees Celsius). I’ve already posted a link above about the plant in February 2022.
Here you go again
My light is up as far as it can go up i cant move my light anymore
Distance from Canopy?
I will have to have a look to find out
