Light Stress or Deficiency?

Link to my journal: https://www.rollitup.org/t/my-first-root-is-down.983547/

Caramel Kush, 00 Seeds, Indica
Day 18 VEG (sprouted Jan1st I think)
Soil: FoxFarm Ocean Forest, fabric pot 1gal
Water: tap, 138PPM, pH'd to 6.5
Nutes: None yet
Light: switched to Quantum board v288 a few days ago, was Mars Pro II 600
Temp 75-85 F about 50%RH
Experience level: My first grow.


A few days ago I swapped out my Mars light for a Quantum Board, and the day after started LST. The growth has been fabulous for the past several days with shoots growing like gangbusters. Also the past few days the humidifier hasn't needed to be refilled and the RH has been about 50% without it. It was last watered Monday and is not quite dry about an inch down. The new growth has always been a brighter green than the old- but today I noticed that all the leaves don't look quite as vibrant. Overall the plant looks a bit peakish. Today I don't see the explosive growth I've been seeing for the past few days.

1. Light Stress? I just changed lights, but for three days it looked like she was loving it. Currently the fixture is 12" from the top and it's dimmed to about 70%. I just raised it to 18" to give it a break.

2. Deficiency? I haven't started adding nutrients yet. Is it time? This is really what I think it is but would like some feedback. I don't want to compound a problem by creating another.

3. Transplant? Maybe it's just time to move to a bigger home... It really doesn't look that big, but she's been in the fabric pot for a few weeks now. Perhaps the roots are hitting the edges of the fabric pot and drying out. I've been going back and forth over this weekend or next to transplant.

oops, here's pictures!

If it were me, I wouldn't be concerned with the color of the plant; in that respect it looks fine. It's the posture of your plant leaves that would concern me. The fact that they are drooped down would perhaps suggest they don't like your light, they want water or they have too much water. If they were happy for 3 days under your new light and you didn't change anything about the new light once it was hung, I doubt that's your culprit, though maybe since you moved the light distance you saw an improvement? You don't look like you're struggling with a deficiency at this point, and I believe, though I don't have practical experience using Fox Farm Ocean Forest, that your soil has enough nutrients in it to get you going for a bit, so I highly doubt you're dealing with a deficiency. I would circle back to your watering habits...be sure she's not too wet and not too dry; but just right. Just my two cents. Good luck friend.

Thanks CannaCountry.

I've seen droopiness on and off with this girl from the beginning. I really think my watering is spot-on though. I allow the soil to get dry about an inch down and the pot feels light, and then soak it in slowly until there's runoff. Sometimes immediately following a watering it droops, sometimes the droop occurs at the end of her day. Hopefully I'll see some improvement with the new adjustment to the height of the lamp.

She's likely getting water this evening (her tomorrow) as the medium's drying out. Humidifier's coming on more so that's probably related, fabric pot and all.

I'll hold off on the nutes if this doesn't look like deficiency. I don't want to make too many changes at once and not know the solution. I'm still confused as to when will be the right time to start though.

I’d have to agree with cannacountry looks healthy but unhappy. I’d say a watering issue and/or the heat swings from 75 to 85. I had an issue that looked similar because I was running too much light and my BD clones were not happy. I turned off half my lights and stabilized my temps to stay under 80 and they seemed to pick up and recover greatly.

Just my half a cent! Good luck!

Edit: I just reread and CannaCounty mentioned lighting as well. So I am agreeing with him. Spot on!

Raise the light! 22" suggested.

https://ledlightsnation.com/tips-on-growing-marijuana-indoors/

https://www.ilovegrowingmarijuana.com/nutrients-deficiency-calcium/

i agree with raising the light

i read this thread as well as your journal and i cant find where you say which driver you have powering your QB? and how big is your tent?
for veg i think ~ 20 watts per square foot @ 24"
for flower ~ 40 watts per square foot @ 18"

The HLG 260W kit came with the Meanwell HLG-240H driver. It's dimmed down to about 70%. I have a kill-a-watt coming next week that'll tell me more, but the kit is rated at 285W full power.

I'm in a 2x2.5' tent.

Based on those numbers should I dim it all the way to 50% and raise the light to 24"?

yeah that sounds about right! your light is pretty powerful for your space.

Just wanted to say thanks to you guys for your help. I’ve raised the light to 24” and dimmed to 50%. Hope to update the thread in a few days with the results.

Deficiency for sure.
Feed them girls. 1/4 strength.

I’ll update the thread with more pics tomorrow, but my lady is standing tall(er) and perky today! The leaf color has improved, but still looks a bit off.

Pics from today, leaf color has returned to normal and she's looking great. I'm not seeing any signs of deficiency. According to The Cannabis Grow Bible by Greg Green the nutrient program should not begin until the newest leaves begin to yellow. I thought this would have begun to occur already, as I'm day 21 VEG- she popped Jan 5th.

So I know I'm in a small tent, and this is a powerful light- but at some point in VEG I'll be lowering the fixture and giving some more power right? I'll have a Kill-A-Watt meter in hand in a few days, and am hoping to get a buddy over with a PAR meter. I'd like to map dimmer levels (50, 70, and 100%) with actual Wattage numbers at three heights (12, 18, and 24") to provide a guide for my setup.

It does look much happier!

Plants don’t need that much light in veg cause the longer day and they’re just slowly growing.
Your light matters most and yours will really shine when you flip to flower and your plant is stretching then building buds!

To do what you wanna do download a lux meter on your phone. From your light, plants want about 30k lux in veg and 60-70k lux in flower. You can check what wattage that is with your killawatt.

Did you feed it?

Still haven’t begun the nutrient program yet. It’s not showing any deficiencies. The newest leaves are a bit lighter than the older, if anything develops toward yellow I’m ready to start.
I’m considering starting 1/3rd dosage in the next week, I’d just rather see the deficiency develop first.

She looks great though. Haven’t updated my grow journal in a few days but will upload some new pictures tomorrow. I’ve got the light at 24” and dimmed to 125W (got a killawatt) with temps pretty even around 77 and raised the humidity to 60%.

I’ve got an infrared temp gun to measure leaf temperature, looking more into VPD. Looks like I’m buying a PPF meter this week, too. Most likely the Apogee MQ-500. Getting into some of the science of growing cannabis.

Waiting to see deficiency isn't the best practice.

She looks hungry.

Ok I'm going to start feeding tonight, a 1/4 dose.

I got an Apogee PAR meter last week, at 125W 24" (actually 20" due to growth oops) I was getting 430 umoles at the top three stems and considerably less to the lower sections of the plant. Tied down the top three and increased wattage to 150W for about 500 umoles at the top of the even canopy, still at 20". Seems to look ok, a little stressed at bedtime this morning, especially the three that got tied.
Will continue to monitor.

Still don't know how to write Unicode outside Windows OS lol

Plant looks fine.

First pictures look like a watering issue to be honest.

I’m no expert in this department but I’d it was a light issue or light burn, the top leafs would be burning or going yellow first.

If you had a N deficiency the bottom leaves would be going yellow first. None of the leaves were yellow, therefore no nutrient issue. Leaves were probably dropping because they were too heavy. I noticed that on my girl yesterday cause I did a huge watering on a 5 gallon smart pot for the first time. Over did it a tad. But they always perk back up. Let that shit dry out.

Keep you lights at 30inches above your canopy and run them at 150 watts, after a few days you should see them become a lot happier. Lots of people run into this problem and think it's nutrient and ph problems, that it is not. It is light stress from the intensity of the qb boards and the leds on the boards being so tighly packed. My qb,s will do the same thing to my plants in fact it's happening now, so I know now to reduce my power. Once your plants are more mature with more roots etc they should cope with more power, but not always. My led single strips at the same power do not cause these problems. My Qb's are being retired and replaced with more strips. Look in my current diary if you like.