# Flowering and Light strength **URL:** \ **Category:** Flowering\ **Tags:** indoor-grow\ **Created:** [June 3, 2022, 7:06am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156 "2022-06-03T07:06:30Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![N00b](https://avatars.discourse-cdn.com/v4/letter/n/2bfe46/32.png) [@N00b](https://ilgmforum.com/u/N00b)\ **Post date:** [June 3, 2022, 7:06am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/1 "2022-06-03T07:06:30Z")
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 ---
**Author:** ![MidwestGuy](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/midwestguy/32/914277_2.png) [@MidwestGuy](https://ilgmforum.com/u/MidwestGuy)\ **Post date:** [June 3, 2022, 7:26am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/2 "2022-06-03T07:26:49Z")
> [@Start using DLI](https://ilgmforum.com/t/start-using-dli/64987): > > Daily Light Interval (DLI) is a quick and efficient way to calculate how much light our plants are receiving within a 24hr period, allowing for easy light adjustments. DLI will help you and the community to better understand your lighting in a more universal term, leading to clearer communication of what the true light value is. Almost all smartphones have the ability to use an app (we will get to this don’t jump the gun) in order to calculate DLI, and if that is not an option a cheap LUX meter… ---
**Author:** ![GreenSnek](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/greensnek/32/366307_2.png) [@GreenSnek](https://ilgmforum.com/u/GreenSnek)\ **Post date:** [June 3, 2022, 7:41am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/3 "2022-06-03T07:41:03Z")
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 ---
**Author:** ![N00b](https://avatars.discourse-cdn.com/v4/letter/n/2bfe46/32.png) [@N00b](https://ilgmforum.com/u/N00b)\ **Post date:** [June 3, 2022, 5:43pm UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/4 "2022-06-03T17:43:30Z")
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. ---
**Author:** ![MidwestGuy](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/midwestguy/32/914277_2.png) [@MidwestGuy](https://ilgmforum.com/u/MidwestGuy)\ **Post date:** [June 3, 2022, 7:29pm UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/5 "2022-06-03T19:29:16Z")
> [@N00b](#): > > measuring the space between each node I use lighting to manipulate node spacing too. ---
**Author:** ![Sizzzl](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/sizzzl/32/713910_2.png) [@Sizzzl](https://ilgmforum.com/u/Sizzzl)\ **Post date:** [June 3, 2022, 7:49pm UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/6 "2022-06-03T19:49:45Z")
Photone App ---
**Author:** ![N00b](https://avatars.discourse-cdn.com/v4/letter/n/2bfe46/32.png) [@N00b](https://ilgmforum.com/u/N00b)\ **Post date:** [June 4, 2022, 10:16am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/7 "2022-06-04T10:16:32Z")
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: > [@Light stress? / PH Fluctuations? / Nutrient Toxicity?](https://ilgmforum.com/t/light-stress-ph-fluctuations-nutrient-toxicity/85348): > > Why is the new growth gnarly looking? The fan leaves are even doing a weird twist, the changes i made in the last few days were I topped the plant Increased light intensity to 100 perc from 70 perc Added more Calcium Nitrate to the Sol. Ph drift remains in between 5.6 to 6.4 ( If i leave it unattended for 3 or more days) -What strain, Seed bank, or bag seed (photo or auto) White Widow, Ministry of Cannabis -Age of plant 6 Weeks -Method: Soil w/salt, Organic soil, Hydroponics, Aquaponic… You can see the same symptoms in the photos i took today: ![WhatsApp Image 2022-06-04 at 3.05.47 PM](https://global.discourse-cdn.com/growingmarijuana/original/4X/3/2/5/32515bbfca7c3bf01c210f6bbd8aec3c6ba86ae3.jpeg) ![WhatsApp Image 2022-06-04 at 3.05.48 PM](https://global.discourse-cdn.com/growingmarijuana/original/4X/9/9/7/997ca68dd7831c9e2f874740e0c11080ad1003ac.jpeg) 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? ---
**Author:** ![N00b](https://avatars.discourse-cdn.com/v4/letter/n/2bfe46/32.png) [@N00b](https://ilgmforum.com/u/N00b)\ **Post date:** [June 4, 2022, 10:26am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/8 "2022-06-04T10:26:28Z")
-What strain, Seed bank, or bag seed (photo or auto) - White Widow, Ministry of Cannabis -Age of plant - 12 Weeks -Method: Soil w/salt, Organic soil, Hydroponics, Aquaponics, KNF - Hydroponics -Vessels: Type and capacity of container (fabric, plastic, etc) - 80 Litre reservoir -PH and TDS of Water, Solution, runoff (if Applicable) - PH 5.8, PPM 618 -PPM/TDS or EC of nutrient solution if applicable +PPM 618 using flowering nutes -Method used to measure PH and TDS - PH pen (HANNA), TDS (Local brand pen) both digital -Indoor or Outdoor if indoor, size of grow space - Indoor (2 by 2 feet) -Light system List brand and wattage/spectrum - KingBrite 240 W Samsung LM301H mix Epistar 660nm Red KingBright Pre-assembled LED Grow Light -Actual wattage draw of lights - I dont know -Current Light Schedule - 12/12 -Temps; Day, Night - 32 Deg C, 28 Dec C -Humidity; Day, Night - 50 Percent Avg. always -Ventilation system; Yes, No, Size - No -AC, Humidifier, De-humidifier, - No -Co2; Yes, No +No If growing Hydro some additional questions: -DWC? RDWC? Autopots? Ebb and Flow? Other? - Ebb and FLow -Distance of liquid below net pot (DWC) +N/A -Temperature of reservoir - 18 to 20 Deg C -TDS of nutrient solution On June 3rd PPM was 618 -Amount of air to solution - I dont know, 3x air pump which bubbles 24/ 7 ---
**Author:** ![MidwestGuy](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/midwestguy/32/914277_2.png) [@MidwestGuy](https://ilgmforum.com/u/MidwestGuy)\ **Post date:** [June 4, 2022, 10:28am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/9 "2022-06-04T10:28:24Z")
> [@N00b](#): > > leaf curls at the ends 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. ![Hydro pH](https://global.discourse-cdn.com/growingmarijuana/original/4X/0/9/0/090138cdd2799085a6d99bbd9f84e9a12955306b.jpeg) ---
**Author:** ![N00b](https://avatars.discourse-cdn.com/v4/letter/n/2bfe46/32.png) [@N00b](https://ilgmforum.com/u/N00b)\ **Post date:** [June 4, 2022, 10:42am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/10 "2022-06-04T10:42:34Z")
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? ---
**Author:** ![MidwestGuy](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/midwestguy/32/914277_2.png) [@MidwestGuy](https://ilgmforum.com/u/MidwestGuy)\ **Post date:** [June 4, 2022, 10:44am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/11 "2022-06-04T10:44:09Z")
> [@N00b](#): > > Bruce Bugbee He’s a pretty smart dude. ---
**Author:** ![N00b](https://avatars.discourse-cdn.com/v4/letter/n/2bfe46/32.png) [@N00b](https://ilgmforum.com/u/N00b)\ **Post date:** [June 4, 2022, 10:51am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/12 "2022-06-04T10:51:28Z")
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? ---
**Author:** ![Aussie\_autos](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/aussie_autos/32/612108_2.png) [@Aussie\_autos](https://ilgmforum.com/u/Aussie_autos)\ **Post date:** [June 4, 2022, 11:01am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/13 "2022-06-04T11:01:17Z")
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 ---
**Author:** ![N00b](https://avatars.discourse-cdn.com/v4/letter/n/2bfe46/32.png) [@N00b](https://ilgmforum.com/u/N00b)\ **Post date:** [June 5, 2022, 4:04am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/14 "2022-06-05T04:04:03Z")
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? ---
**Author:** ![Docnraq](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/docnraq/32/1206410_2.png) [@Docnraq](https://ilgmforum.com/u/Docnraq)\ **Post date:** [June 5, 2022, 5:17am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/15 "2022-06-05T05:17:55Z")
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. ---
**Author:** ![N00b](https://avatars.discourse-cdn.com/v4/letter/n/2bfe46/32.png) [@N00b](https://ilgmforum.com/u/N00b)\ **Post date:** [June 6, 2022, 5:49pm UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/16 "2022-06-06T17:49:21Z")
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** ---
**Author:** ![N00b](https://avatars.discourse-cdn.com/v4/letter/n/2bfe46/32.png) [@N00b](https://ilgmforum.com/u/N00b)\ **Post date:** [June 6, 2022, 5:51pm UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/17 "2022-06-06T17:51:50Z")
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 > [@Light stress? / PH Fluctuations? / Nutrient Toxicity?](https://ilgmforum.com/t/light-stress-ph-fluctuations-nutrient-toxicity/85348): > > Why is the new growth gnarly looking? The fan leaves are even doing a weird twist, the changes i made in the last few days were I topped the plant Increased light intensity to 100 perc from 70 perc Added more Calcium Nitrate to the Sol. Ph drift remains in between 5.6 to 6.4 ( If i leave it unattended for 3 or more days) -What strain, Seed bank, or bag seed (photo or auto) White Widow, Ministry of Cannabis -Age of plant 6 Weeks -Method: Soil w/salt, Organic soil, Hydroponics, Aquaponic… ---
**Author:** ![Aussie\_autos](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/aussie_autos/32/612108_2.png) [@Aussie\_autos](https://ilgmforum.com/u/Aussie_autos)\ **Post date:** [June 6, 2022, 8:31pm UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/18 "2022-06-06T20:31:53Z")
My light is up as far as it can go up i cant move my light anymore ---
**Author:** ![N00b](https://avatars.discourse-cdn.com/v4/letter/n/2bfe46/32.png) [@N00b](https://ilgmforum.com/u/N00b)\ **Post date:** [June 7, 2022, 4:37am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/19 "2022-06-07T04:37:08Z")
Distance from Canopy? ---
**Author:** ![Aussie\_autos](https://sea2.discourse-cdn.com/growingmarijuana/user_avatar/ilgmforum.com/aussie_autos/32/612108_2.png) [@Aussie\_autos](https://ilgmforum.com/u/Aussie_autos)\ **Post date:** [June 7, 2022, 4:40am UTC](https://ilgmforum.com/t/flowering-and-light-strength/88156/20 "2022-06-07T04:40:56Z")
I will have to have a look to find out [Next page](https://ilgmforum.com/t/flowering-and-light-strength/88156.md?page=2)