Seedling looking a little worse for wear / too much light?

[SecretFarmer]

Hi folks,

Long time listener, first time caller.

Details:
Area - 40x40x140 grow tent (yes, 40cmx40cm)
Medium - 11L Airpot with Biobizz light mix (+~30% perlite)
Lighting - 100w HLG QB (24/0)
5" extraction fan leading to carbon filter
Strain - Sweet Seeds +Speed Auto
Day 14 after sprout - germinated in final pot
Nutes - Biotabs but not applied yet, only pH'd water applied by spray bottle so far. (Have added some microbial/rooting agents to the soil mix)
I also have a heat mat under the pot as an attempt to keep the rootzone warm - not sure how effective this is with the airpot design but letting it run as it's v cold here.

Air temps 20c - 25c, RH ~50%.


So that's my grow specs, everything seems within the acceptable ranges as far as I know. This is my second grow, ran the same strain and same specs (mostly) last time and pulled about 40g with a Marshydro 150w blurple.

I am currently 14 days since sprout with this current grow and noticing some worrying signs on my seedling. I had a humidity dome on for the first 10 days or so FWIW. The true leaves are coming in now and look fine, but the first set of leaves (not cotyledons, the non-palmate true leaves) have shown some signs of stress. There is some curling of the edges and tips, and some bleaching. It seems like light stress to me but I'm unsure.

I have a new light which seems a lot more powerful. I began the grow with the light at minimum power, 24" from the pot. This gave me a rough PPFD reading of 50. Can't get a precise number as my model HLG light is not on their website, but they have some PPFD calculations for their other lights that I've been working off so pretty sure this is in the right range. I've been bumping it up a touch every couple of days, to a max of about 120 PPFD, at which point I backed it off as I noticed these stress signs.

Growth seems a little bit slow compared to my last grow. Day 14 after sprout and she's only 10cm tall. I wonder if I got a super speedy pheno in my last grow, as by week 3 it had veg'd the entire pot!

I realise I have kinda answered my own question here, but maybe there is something I am missing. Any input greaty appreciated. Pics below.

P.S., thanks for all the help over the last year. As an avid lurker I've learned so much from you all!


Edit: change PAR to PPFD
Edit2: I know you should fill the airpot to the brim but I ran out. -_-

 

[Mañ'O'Green]

@SecretFarmer Welcome to AFN Every seed is different. It looks like you may have kept the humidity dome over the plant too long and the leaf edges stayed too wet causing the deformation. Some cups can intensify the light and heat inside? I always remove a dome (when I use one) when the first true leaves grow out. I also switch to 18/6 at that time.

She looks to be off to a slow start but that is a big pot and she is working on roots right now. Be patient.

 

[SecretFarmer]

Thanks for the reply! That is a good point re: humidity dome, maybe wasnt such a good idea. I didn't use one on my first grow, but as mentioned I am growing in a somewhat cold space and thought the extra humidity and temps wouldnt go astray. There were beads of water forming on the leaves at times, I guess I should have removed the dome at that stage.

Let's see how she is in 10 weeks. Thanks again for your msg.

 

[low_and_slow]

Looks like it'll grow out of whatever is happening. Heavy dose of LITFA for a week or two and it'll be in great shape.

 

[SecretFarmer]

Haha, thanks for that, was about to google that acronym when it hit me.

Thanks for the reassurance folks. I might start a grow journal to keep track of how this one develops, might keep me more honest with my LITFA

 

[Chili]

Looks like you’re way to far from light, possibly try lowering your lights to 20” and turning them down to seed adjust strength.
Should be seeing a strong short stocky soldier here. I would bet if you lifted her she would have weakened roots more like fine hair than strong white hairy tentacles of love . To much water Will do this.
I would also recommend a small composting seed starter in clean coco, no newts To hit them baby roots. Sizzle sizzle.

 

[SecretFarmer]

Looks like you’re way to far from light, possibly try lowering your lights to 20” and turning them down to seed adjust strength.
Should be seeing a strong short stocky soldier here. I would bet if you lifted her she would have weakened roots more like fine hair than strong white hairy tentacles of love . To much water Will do this.
I would also recommend a small composting seed starter in clean coco, no newts To hit them baby roots. Sizzle sizzle.

Hey thanks so much for the message. That's an interesting point, I had considered that the light was too far away but from my PPFD calculations it seemed ok. Is it possible to have the correct PPFD hitting the plant but the light is still too far away? I would've thought 100PFD at 1 feet and 10 feet would be the same thing but maybe not.

I am reasonably confident that I have not overwatered this plant. I had soaked the pot about 2 days prior to germination, and she was only getting a light misting every 2-3 days for the first two weeks. It is certainly possible that between the soaking/misting/humidity dome there was too much moisture for the roots to develop properly. I'll be sure to take a good look at the rootball when she's finished. Hoping she can take off over the next couple of weeks.

On a related note: there's a cannabis subreddit for my country that I visit regularly. You know how people growing in DWC show off their rootballs? There was a fellow on their showing off his soil grow rootball at week 4. He literally pulled the plant out of the soil to take a photo. "Looking nice and healthy"


The plant seems to be recovering from the slow start anyway. Since my last post I have changed light schedule to 20/4 which maybe helped. Probably gonna end up a fairly light yielder but she wants to live!! So I'll give her my best care until the end. I haven't done anything except give it a bit of water and crank the light power (which also increased my ambient temps, can't hurt). I am gonna bend her over today. Also she needs a watering and the insertion of the bio tabs. I'm really freaking out about getting the biotabs in the soil without damaging the roots. Gonna dig a little hole at the edge of the pot and see. Alternatively I might crush up one of the tabs and sprinkle it on the soil in a top dressing style. We'll see...

Thanks for your replies folks, I'm still learning! For my next grow I am 100% starting in a smaller pot and potting up. This will let me take full advantage of the heat mat I have and also prevent issues like I've encountered this time.

I hope everyone has a lovely stoned Sunday.


EDIT TO ADD: I tried my best to LITFA, but I did apply some "Plant Magic Evolutin Spray" - a foliar feed for veg. From their website "The bio-stimulants and plant hormones improve photosynthesis, the sugars fuel the growth, the trace elements and amino acids ensure growth is healthy and the humic and fulvic acids help deliver the ingredients directly into plant cells. The super wetting agent achieves rapid wetting, dispersion and improved penetration into the pores of the plant. " A couple of days after I applied this the plant looked 1000% healthier. Coincidence maybe.

 

[Ben Curley]

LITFA........I love it! I have learned the hard way! Used to chase deficiencies the entire grow. Always had to mess with shit.......I have learned that LESS is MORE. Set it and forget it!

 

[SecretFarmer]

For sure Ben! I think especially as a new grower we want to check every 15 minutes to make sure it's okay. The little ladies just want some peace! If you like that acronym here's another good IT one that applies to growing: PEBKAC - problem exists between keyboard and chair. Aka, the only problem is the pilot.

 

[Arthur]

New growers are very susceptible to hoveritis. The inability to go more than a few minutes without attending to something.
Most of us had it. Those that don't get over this ailment are destined to be purchasers at the local dispensary.