Hello growers, I’m growing these girl scout cookies auto flowers from ILGM, currently in week 3 of flower, and all is seemingly going well however I’m concerned about how little light they can handle before showing stress. I Have an SP3000 in a 2x4, and it seems if I go above 50% on the dimmer, the leaves nearest the light start twisting and curling followed by brown spots and pale color between veins.
Coco in 3 gal fabric pots Drip irrigation 3x/day Mars sp3000 at 475ish PPFD (using Photone app and light charts) (35ish DLI) 22" from canopy Ph 5.8-6.2 525 PPM RO water GH Flora trio Humic Calimagic Epsom salt (1g/gal) Armor si Yucca extract
From what I’m reading it points to potentially nitrogen toxicity, light stress, or both? I’ve ordered a refractometer to check the BRIX which will be here tomorrow.
think I may have cooked them a little bit when I increased the light early in flower, but have since backed the dimmer waaay off, and they still stress any time I bump it up even a hair.
Following the coco for cannabis feed chart, and they are getting very little nitrogen now, and a big bump in P and K, which they seem to be loving, but the dark green foliage and light sensitivity has me worried. I think the slight tip yellowing is from light stress as well. Runoff PH is showing 6.1 for both and 490ish PPM EC, so i don’t suspect nute burn, though I am not qualified to say that with any certainty.
Really open to any advice or opinions on what might be going on with my girls. Thanks in advance, and happy growing!
This is my first grow since 2013 and my first run in Coco so maybe I just have something like new parent syndrome lol
Also yes I’m watering till run off, maybe 10 to 15%. Hard to say exactly but there’s a good bit collecting in the drain pan. Run off EC is usually just a tad lower than input.
I just tried to bump the SP3000 up to a hair about 50% and by the time I got home from work The upper sugar leaves closest to the light started twisting and showing signs of stress so I backed it off again. Based off most accounts I’ve read online, people are going 75 to 100% 18 in from canopy with the same setup so I’m puzzled.
I set my lighting by growth stage and DLI, for the age of the plants you have I’m usually hovering around 35-40 and bump that up weekly so that weeks 5-8 are around a DLI of 45-50. And 40 in the corners or a little less. I watch the plants reaction
Hey @Hooterjh101 your girls are looking pretty good. Looks like you have them well taken care of. I did notice you didn’t post temperatures of your tent. With them wilting when you bump up your lights the temperature could be causing them to wilt due to release of water through respiration. Coco dose require plenty of water as it does not hot onto water like basic soil and potting grow mediums.
Do you have fresh air entering from the bottom of the tent and exhaust at the top? Are you using an exhaust fan with temp sensor to crank up when it’s above ~80F?
Cannabis is a C3 plant and will open up when it’s too hot to cool itself down. If you provide enough water and moving enough air around the plant you should be good. But you’ll need to make sure your moving the hot air out and replacing with fresh air.
Here’s a good video that details how this process works.
I’m running an AC Infiniti cloud line t4. Temps hang out between 72 and 78 generally and the fan begins ramping up incrementally as we approach the 80.
Humidity is pretty well controlled between 48 and 55%. VPD hangs out between 1.2 and 1.5.
After considering All of the advice I got here and reading up a bit, I’ve increased my fertigation to four times per day since I’m running 30% perlite in my coco. She certainly was beginning to wilt between waterings. In 3 gallon fabric pots she drinks a ton of water fast!
I bumped the lights up to around 60% which puts me roughly at 37 DLI (photone app), And so far so good they look pretty happy!
Here’s some updated pictures as the old ones are a bit dated now:
I did have a bit of concern about how damn bushy they are and the threat of PM/rot. I’ve done some considerable defoliation (which they took like a champ) But she kept growing new chutes And I don’t want to be snipping at her everyday.
Thanks for all the advice, this community seems pretty solid!
Edit: same strain, wildly different phenos. What an awesome species weed is!
I am also using GH Flora line of nutrients with all the GH additives. Additionally I use Hydroguard for beneficial microbes. Difference is I’m growing in water, DWC, hydroponics. I try and keep the pH between 5.8-6.1. I’ve found in my system pH drifts down. So I try and start at 6.1. Coco should also be 5.8-6.1pH inside the bucket. That’s where your need to capture runoff to know exactly what pH is inside your bucket. With me I can always dip my meter into the bucket and get a very accurate reading.
